{"id":205,"date":"2026-02-01T12:05:57","date_gmt":"2026-02-01T04:05:57","guid":{"rendered":"http:\/\/47.100.165.17\/wordpress\/?p=205"},"modified":"2026-02-01T12:05:57","modified_gmt":"2026-02-01T04:05:57","slug":"%e3%80%90mysql%e3%80%91%e8%bf%90%e7%ae%97%e5%85%a8%e8%a7%a3%e6%9e%90","status":"publish","type":"post","link":"https:\/\/yunyanglib.cn\/?p=205","title":{"rendered":"\u3010MySQL\u3011\u8fd0\u7b97\u5168\u89e3\u6790"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\" id=\"I7M6P\">1.1 \u7b97\u672f\u8fd0\u7b97\u7b26\u53ca\u5e94\u7528\u8be6\u89e3<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"u16a61fa9\">\u7b97\u672f\u8fd0\u7b97\u7b26\u662fMySQL\u4e2d\u6700\u57fa\u7840\u7684\u8fd0\u7b97\u5de5\u5177\uff0c\u5e38\u7528\u4e8e\u6570\u636e\u8ba1\u7b97\u3001\u5b57\u6bb5\u503c\u5904\u7406\u7b49\u573a\u666f\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u52a0\u6cd5\uff08+\uff09<\/strong><br>\u7528\u4e8e\u8ba1\u7b97\u4e24\u4e2a\u503c\u7684\u548c\uff0c\u652f\u6301\u5e38\u91cf\u3001\u5b57\u6bb5\u4e0e\u5e38\u91cf\u3001\u5b57\u6bb5\u4e0e\u5b57\u6bb5\u4e4b\u95f4\u7684\u8fd0\u7b97\u3002<br>\u793a\u4f8b\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"t6fYV\" class=\"wp-block-code\"><code>-- \u5e38\u91cf\u76f8\u52a0\nselect 1+1; -- \u7ed3\u679c\u4e3a2<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"udb0d4ce6\">\u5b9e\u9645\u4e1a\u52a1\u4e2d\uff0c\u5e38\u9700\u5bf9\u8868\u4e2d\u5b57\u6bb5\u8fdb\u884c\u6c42\u548c\u8fd0\u7b97\u3002\u5148\u521b\u5efa\u6d4b\u8bd5\u8868\u5e76\u63d2\u5165\u6570\u636e\uff1a<\/p>\n\n\n\n<pre id=\"j6NOF\" class=\"wp-block-code\"><code>-- \u521b\u5efa\u6d4b\u8bd5\u8868\ncreate table count_test(a int, b int);\n\n-- \u63d2\u5165\u6d4b\u8bd5\u6570\u636e\ninsert into count_test values (5,2),(4,3);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"u0a540ffc\">\u57fa\u4e8e\u6d4b\u8bd5\u8868\u7684\u52a0\u6cd5\u8fd0\u7b97\uff1a<\/p>\n\n\n\n<pre id=\"ViN1E\" class=\"wp-block-code\"><code>-- \u8ba1\u7b97\u5b57\u6bb5a\u548c\u5b57\u6bb5b\u7684\u548c\nselect a + b from count_test; -- \u7ed3\u679c\u4e3a7\u30017\n\n-- \u8ba1\u7b97\u5b57\u6bb5a\u4e0e\u5e38\u91cf3\u7684\u548c\nselect a + 3 from count_test; -- \u7ed3\u679c\u4e3a8\u30017<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u51cf\u6cd5\uff08-\uff09<\/strong><br>\u7528\u4e8e\u8ba1\u7b97\u4e24\u4e2a\u503c\u7684\u5dee\u503c\uff0c\u7528\u6cd5\u4e0e\u52a0\u6cd5\u7c7b\u4f3c\u3002<br>\u793a\u4f8b\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"uYRYX\" class=\"wp-block-code\"><code>-- \u5e38\u91cf\u76f8\u51cf\nselect 2-1; -- \u7ed3\u679c\u4e3a1\n\n-- \u8ba1\u7b97\u5b57\u6bb5a\u4e0e\u5b57\u6bb5b\u7684\u5dee\u503c\nselect a - b from count_test; -- \u7ed3\u679c\u4e3a3\u30011<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4e58\u6cd5\uff08*\uff09<\/strong><br>\u7528\u4e8e\u8ba1\u7b97\u4e24\u4e2a\u503c\u7684\u4e58\u79ef\u3002<br>\u793a\u4f8b\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"se7ut\" class=\"wp-block-code\"><code>-- \u5e38\u91cf\u76f8\u4e58\nselect 2*2; -- \u7ed3\u679c\u4e3a4\n\n-- \u8ba1\u7b97\u5b57\u6bb5a\u4e0e\u5b57\u6bb5b\u7684\u4e58\u79ef\nselect a * b from count_test; -- \u7ed3\u679c\u4e3a10\u300112<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9664\u6cd5\uff08\/\uff09<\/strong><br>\u7528\u4e8e\u8ba1\u7b97\u4e24\u4e2a\u503c\u7684\u5546\uff08\u6ce8\u610f\uff1aMySQL\u4e2d\u9664\u6cd5\u7ed3\u679c\u4e3a\u6d6e\u70b9\u6570\uff09\u3002<br>\u793a\u4f8b\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"Vcba0\" class=\"wp-block-code\"><code>-- \u5e38\u91cf\u76f8\u9664\nselect 4\/2; -- \u7ed3\u679c\u4e3a2.0\n\n-- \u8ba1\u7b97\u5b57\u6bb5a\u4e0e\u5b57\u6bb5b\u7684\u5546\nselect a \/ b from count_test; -- \u7ed3\u679c\u4e3a2.5\u30011.333...<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u53d6\u4f59\uff08% \u6216 MOD\uff09<\/strong><br>\u7528\u4e8e\u8ba1\u7b97\u4e24\u4e2a\u503c\u76f8\u9664\u540e\u7684\u4f59\u6570\u3002<br>\u793a\u4f8b\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"Gn0yq\" class=\"wp-block-code\"><code>-- \u5e38\u91cf\u53d6\u4f59\nselect 4%3; -- \u7ed3\u679c\u4e3a1\n\n-- \u8ba1\u7b97\u5b57\u6bb5a\u4e0e\u5b57\u6bb5b\u7684\u4f59\u6570\nselect a % b from count_test; -- \u7ed3\u679c\u4e3a1\u30011<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"rKbrh\">1.2 \u6bd4\u8f83\u8fd0\u7b97\u7b26\u7684\u5e94\u7528<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"u5c806d5d\">\u6bd4\u8f83\u8fd0\u7b97\u7b26\u7528\u4e8e\u5224\u65ad\u4e24\u4e2a\u503c\u7684\u5173\u7cfb\uff0c\u8fd4\u56de\u7ed3\u679c\u4e3a\u5e03\u5c14\u503c\uff081\u8868\u793a\u771f\uff0c0\u8868\u793a\u5047\uff09\uff0c\u5e38\u7528\u4e8e\u67e5\u8be2\u6761\u4ef6\u8fc7\u6ee4\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"NF2Mn\">1.2.1 \u5e38\u7528\u6bd4\u8f83\u8fd0\u7b97\u7b26<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>=<\/code>\uff1a\u5224\u65ad\u4e24\u4e2a\u503c\u662f\u5426\u76f8\u7b49<\/li>\n\n\n\n<li><code>&lt;><\/code> \u6216 <code>!=<\/code>\uff1a\u5224\u65ad\u4e24\u4e2a\u503c\u662f\u5426\u4e0d\u76f8\u7b49<\/li>\n\n\n\n<li><code>><\/code>\uff1a\u5224\u65ad\u5de6\u4fa7\u503c\u662f\u5426\u5927\u4e8e\u53f3\u4fa7\u503c<\/li>\n\n\n\n<li><code>&lt;<\/code>\uff1a\u5224\u65ad\u5de6\u4fa7\u503c\u662f\u5426\u5c0f\u4e8e\u53f3\u4fa7\u503c<\/li>\n\n\n\n<li><code>>=<\/code>\uff1a\u5224\u65ad\u5de6\u4fa7\u503c\u662f\u5426\u5927\u4e8e\u7b49\u4e8e\u53f3\u4fa7\u503c<\/li>\n\n\n\n<li><code>&lt;=<\/code>\uff1a\u5224\u65ad\u5de6\u4fa7\u503c\u662f\u5426\u5c0f\u4e8e\u7b49\u4e8e\u53f3\u4fa7\u503c<\/li>\n\n\n\n<li><code>BETWEEN ... AND ...<\/code>\uff1a\u5224\u65ad\u503c\u662f\u5426\u5728\u6307\u5b9a\u8303\u56f4\u5185\uff08\u5305\u542b\u8fb9\u754c\uff09<\/li>\n\n\n\n<li><code>IN<\/code>\uff1a\u5224\u65ad\u503c\u662f\u5426\u5c5e\u4e8e\u6307\u5b9a\u96c6\u5408\u4e2d\u7684\u67d0\u4e00\u4e2a<\/li>\n\n\n\n<li><code>IS NULL<\/code>\uff1a\u5224\u65ad\u503c\u662f\u5426\u4e3aNULL<\/li>\n\n\n\n<li><code>IS NOT NULL<\/code>\uff1a\u5224\u65ad\u503c\u662f\u5426\u4e0d\u4e3aNULL<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"nrp20\">1.2.2 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"uc3a1ad4e\">\u521b\u5efa\u6d4b\u8bd5\u8868\u7528\u4e8e\u9a8c\u8bc1\u6bd4\u8f83\u8fd0\u7b97\u7b26\uff1a<\/p>\n\n\n\n<pre id=\"qPQwS\" class=\"wp-block-code\"><code>create table compare_test(\n  a int,\n  b int\n) engine=innodb;\n\n-- \u63d2\u5165\u6d4b\u8bd5\u6570\u636e\ninsert into compare_test values (1,1),(3,2);<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7b49\u4e8e\uff08=\uff09<\/strong><br>\u5224\u65ad\u4e24\u4e2a\u5b57\u6bb5\u503c\u662f\u5426\u76f8\u7b49\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"K3i1E\" class=\"wp-block-code\"><code>select a=b from compare_test; -- \u7ed3\u679c\u4e3a1\uff08\u771f\uff09\u30010\uff08\u5047\uff09<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4e0d\u7b49\u4e8e\uff08&lt;> \u6216 !=\uff09<\/strong><br>\u5224\u65ad\u4e24\u4e2a\u5b57\u6bb5\u503c\u662f\u5426\u4e0d\u76f8\u7b49\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"NjMdc\" class=\"wp-block-code\"><code>select a&lt;&gt;b from compare_test; -- \u7ed3\u679c\u4e3a0\uff08\u5047\uff09\u30011\uff08\u771f\uff09<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5927\u4e8e\uff08>\uff09<\/strong><br>\u5224\u65ad\u5b57\u6bb5a\u662f\u5426\u5927\u4e8e\u5b57\u6bb5b\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"B400z\" class=\"wp-block-code\"><code>select a&gt;b from compare_test; -- \u7ed3\u679c\u4e3a0\uff08\u5047\uff09\u30011\uff08\u771f\uff09<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u8303\u56f4\u5224\u65ad\uff08BETWEEN &#8230; AND &#8230;\uff09<\/strong><br>\u5224\u65ad\u5b57\u6bb5a\u7684\u503c\u662f\u5426\u57282\u52304\u4e4b\u95f4\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"im6jL\" class=\"wp-block-code\"><code>select a between 2 and 4 from compare_test; -- \u7ed3\u679c\u4e3a0\uff08\u5047\uff09\u30011\uff08\u771f\uff09<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u96c6\u5408\u5224\u65ad\uff08IN\uff09<\/strong><br>\u5224\u65ad\u5b57\u6bb5a\u7684\u503c\u662f\u5426\u5c5e\u4e8e{1,5,9}\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"fopFp\" class=\"wp-block-code\"><code>select a in (1,5,9) from compare_test; -- \u7ed3\u679c\u4e3a1\uff08\u771f\uff09\u30010\uff08\u5047\uff09<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7a7a\u503c\u5224\u65ad\uff08IS NULL \/ IS NOT NULL\uff09<\/strong><br>\u5148\u521b\u5efa\u542bNULL\u503c\u7684\u6d4b\u8bd5\u8868\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"ZbXqx\" class=\"wp-block-code\"><code>create table null_test(a varchar(10));\ninsert into null_test values ('aaa'), (null);<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"uea48430e\">\u5224\u65ad\u5b57\u6bb5\u662f\u5426\u4e3a\u7a7a\u6216\u975e\u7a7a\uff1a<\/p>\n\n\n\n<pre id=\"OwdHg\" class=\"wp-block-code\"><code>select a is null from null_test; -- \u7ed3\u679c\u4e3a0\uff08\u5047\uff09\u30011\uff08\u771f\uff09\nselect a is not null from null_test; -- \u7ed3\u679c\u4e3a1\uff08\u771f\uff09\u30010\uff08\u5047\uff09<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"vdEVI\">1.3 \u903b\u8f91\u8fd0\u7b97\u7b26\u7684\u5e94\u7528<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"u99abe441\">\u903b\u8f91\u8fd0\u7b97\u7b26\u7528\u4e8e\u7ec4\u5408\u591a\u4e2a\u6761\u4ef6\uff0c\u5224\u65ad\u7ed3\u679c\u7684\u771f\u5047\u5173\u7cfb\uff0c\u5e38\u7528\u4e8e\u590d\u6742\u67e5\u8be2\u7684\u6761\u4ef6\u8fc7\u6ee4\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"RgjT2\">1.3.1 \u5e38\u7528\u903b\u8f91\u8fd0\u7b97\u7b26<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u903b\u8f91\u975e\uff08! \u6216 NOT\uff09<\/strong>\uff1a\u5bf9\u5355\u4e00\u6761\u4ef6\u53d6\u53cd\uff08\u771f\u2192\u5047\uff0c\u5047\u2192\u771f\uff09<\/li>\n\n\n\n<li><strong>\u903b\u8f91\u4e0e\uff08AND\uff09<\/strong>\uff1a\u9700\u6240\u6709\u6761\u4ef6\u540c\u65f6\u4e3a\u771f\uff0c\u7ed3\u679c\u624d\u4e3a\u771f<\/li>\n\n\n\n<li><strong>\u903b\u8f91\u6216\uff08OR\uff09<\/strong>\uff1a\u53ea\u8981\u4efb\u4e00\u6761\u4ef6\u4e3a\u771f\uff0c\u7ed3\u679c\u5c31\u4e3a\u771f<\/li>\n\n\n\n<li><strong>\u903b\u8f91\u5f02\u6216\uff08XOR\uff09<\/strong>\uff1a\u4e24\u4e2a\u6761\u4ef6\u4e00\u771f\u4e00\u5047\u65f6\u7ed3\u679c\u4e3a\u771f\uff0c\u5426\u5219\u4e3a\u5047<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"w0mBY\">1.3.2 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"uc657511e\">\u521b\u5efa\u6d4b\u8bd5\u8868\u7528\u4e8e\u9a8c\u8bc1\u903b\u8f91\u8fd0\u7b97\u7b26\uff1a<\/p>\n\n\n\n<pre id=\"prpDB\" class=\"wp-block-code\"><code>create table logic_test(\n  a int,\n  b int\n) engine=innodb;\n\n-- \u63d2\u5165\u6d4b\u8bd5\u6570\u636e\ninsert into logic_test values (2,2), (1,2);<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u903b\u8f91\u975e\uff08! \u6216 NOT\uff09<\/strong><br>\u5bf9\u6761\u4ef6\u53d6\u53cd\uff08\u771f\u21920\uff0c\u5047\u21921\uff09\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"i5556\" class=\"wp-block-code\"><code>-- \u5224\u65ad1+2\u662f\u5426\u4e0d\u7b49\u4e8e2\uff08\u7ed3\u679c\u4e3a\u771f\uff0c\u8fd4\u56de1\uff09\nselect (1 + 2) != 2; -- \u7ed3\u679c\u4e3a1\n\n-- \u5224\u65ad1+2\u662f\u5426\u4e0d\u7b49\u4e8e3\uff08\u7ed3\u679c\u4e3a\u5047\uff0c\u8fd4\u56de0\uff09\nselect (1 + 2) != 3; -- \u7ed3\u679c\u4e3a0\n\n-- \u5224\u65ad\u5b57\u6bb5a\u4e0eb\u662f\u5426\u4e0d\u76f8\u7b49\nselect a != b from logic_test; -- \u7ed3\u679c\u4e3a0\u30011\n\n-- \u8fc7\u6ee4\u51faa\u4e0eb\u4e0d\u76f8\u7b49\u7684\u884c\nselect * from logic_test where a != b; -- \u8fd4\u56de\u7b2c2\u884c\u6570\u636e<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u903b\u8f91\u4e0e\uff08AND\uff09<\/strong><br>\u9700\u4e24\u4e2a\u6761\u4ef6\u540c\u65f6\u4e3a\u771f\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"CIPnv\" class=\"wp-block-code\"><code>-- 1=1\u4e3a\u771f\uff0c2=1\u4e3a\u5047\uff0c\u7ed3\u679c\u4e3a0\nselect 1=1 and 2=1; -- \u7ed3\u679c\u4e3a0\n\n-- \u8fc7\u6ee4\u51faa=1\u4e14b=2\u7684\u884c\nselect * from logic_test where a=1 and b=2; -- \u8fd4\u56de\u7b2c2\u884c\u6570\u636e<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u903b\u8f91\u6216\uff08OR\uff09<\/strong><br>\u4efb\u4e00\u6761\u4ef6\u4e3a\u771f\u5219\u7ed3\u679c\u4e3a\u771f\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"V8PZo\" class=\"wp-block-code\"><code>-- 1=1\u4e3a\u771f\uff0c2=1\u4e3a\u5047\uff0c\u7ed3\u679c\u4e3a1\nselect 1=1 or 2=1; -- \u7ed3\u679c\u4e3a1\n\n-- \u8fc7\u6ee4\u51faa=1\u6216b=2\u7684\u884c\nselect * from logic_test where a=1 or b=2; -- \u8fd4\u56de\u4e24\u884c\u6570\u636e<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u903b\u8f91\u5f02\u6216\uff08XOR\uff09<\/strong><br>\u6761\u4ef6\u4e00\u771f\u4e00\u5047\u65f6\u7ed3\u679c\u4e3a\u771f\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"F8GSh\" class=\"wp-block-code\"><code>-- 1=1\u4e3a\u771f\uff0c2=1\u4e3a\u5047\uff0c\u7ed3\u679c\u4e3a1\nselect 1=1 xor 2=1; -- \u7ed3\u679c\u4e3a1\n\n-- 1=1\u4e3a\u771f\uff0c2=2\u4e3a\u771f\uff0c\u7ed3\u679c\u4e3a0\nselect 1=1 xor 2=2; -- \u7ed3\u679c\u4e3a0\n\n-- 1=2\u4e3a\u5047\uff0c2=3\u4e3a\u5047\uff0c\u7ed3\u679c\u4e3a0\nselect 1=2 xor 2=3; -- \u7ed3\u679c\u4e3a0<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"UGuAN\">1.4 \u4f4d\u8fd0\u7b97\u7b26\u7684\u5e94\u7528<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"ueaddda3c\">\u4f4d\u8fd0\u7b97\u7b26\u7528\u4e8e\u5bf9\u6570\u503c\u7684\u4e8c\u8fdb\u5236\u4f4d\u8fdb\u884c\u8fd0\u7b97\uff0c\u9002\u7528\u4e8e\u5e95\u5c42\u6570\u636e\u5904\u7406\u6216\u7279\u5b9a\u573a\u666f\uff08\u5982\u6743\u9650\u63a7\u5236\uff09\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"iphRc\">1.4.1 \u5e38\u7528\u4f4d\u8fd0\u7b97\u7b26<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4f4d\u4e0e\uff08&amp;\uff09<\/strong>\uff1a\u4e24\u4e2a\u4e8c\u8fdb\u5236\u4f4d\u5747\u4e3a1\u65f6\uff0c\u7ed3\u679c\u4f4d\u4e3a1\uff0c\u5426\u5219\u4e3a0<br>\u4f8b\uff1a5\uff080101\uff09 &amp; 3\uff080011\uff09 = 1\uff080001\uff09<\/li>\n\n\n\n<li><strong>\u4f4d\u6216\uff08|\uff09<\/strong>\uff1a\u4e24\u4e2a\u4e8c\u8fdb\u5236\u4f4d\u81f3\u5c11\u6709\u4e00\u4e2a\u4e3a1\u65f6\uff0c\u7ed3\u679c\u4f4d\u4e3a1<br>\u4f8b\uff1a5\uff080101\uff09 | 3\uff080011\uff09 = 7\uff080111\uff09<\/li>\n\n\n\n<li><strong>\u4f4d\u5f02\u6216\uff08^\uff09<\/strong>\uff1a\u4e24\u4e2a\u4e8c\u8fdb\u5236\u4f4d\u4e0d\u540c\u65f6\uff0c\u7ed3\u679c\u4f4d\u4e3a1\uff0c\u5426\u5219\u4e3a0<br>\u4f8b\uff1a5\uff080101\uff09 ^ 3\uff080011\uff09 = 6\uff080110\uff09<\/li>\n\n\n\n<li><strong>\u4f4d\u53d6\u53cd\uff08~\uff09<\/strong>\uff1a\u5bf9\u4e8c\u8fdb\u5236\u4f4d\u53d6\u53cd\uff081\u21920\uff0c0\u21921\uff09\uff0c\u9700\u6ce8\u610f\u7b26\u53f7\u4f4d\u5904\u7406<\/li>\n\n\n\n<li><strong>\u4f4d\u5de6\u79fb\uff08&lt;&lt;\uff09<\/strong>\uff1a\u5c06\u4e8c\u8fdb\u5236\u4f4d\u5411\u5de6\u79fb\u52a8\u6307\u5b9a\u4f4d\u6570\uff0c\u53f3\u4fa7\u88650<br>\u4f8b\uff1a5\uff080101\uff09 &lt;&lt; 2 = 20\uff0810100\uff09<\/li>\n\n\n\n<li><strong>\u4f4d\u53f3\u79fb\uff08>>\uff09<\/strong>\uff1a\u5c06\u4e8c\u8fdb\u5236\u4f4d\u5411\u53f3\u79fb\u52a8\u6307\u5b9a\u4f4d\u6570\uff0c\u5de6\u4fa7\u88650\uff08\u6b63\u6570\uff09\u6216\u7b26\u53f7\u4f4d\uff08\u8d1f\u6570\uff09<br>\u4f8b\uff1a24\uff0811000\uff09 >> 2 = 6\uff0800110\uff09<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"g8WdP\">1.4.2 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<pre id=\"Sj90h\" class=\"wp-block-code\"><code>-- \u4f4d\u4e0e\u8fd0\u7b97\nselect 5&amp;6; -- 5\uff080101\uff09&amp;6\uff080110\uff09=4\uff080100\uff09\uff0c\u7ed3\u679c\u4e3a4\n\n-- \u4f4d\u6216\u8fd0\u7b97\nselect 5|6; -- 5\uff080101\uff09|6\uff080110\uff09=7\uff080111\uff09\uff0c\u7ed3\u679c\u4e3a7\n\n-- \u4f4d\u5f02\u6216\u8fd0\u7b97\nselect 5^6; -- 5\uff080101\uff09^6\uff080110\uff09=3\uff080011\uff09\uff0c\u7ed3\u679c\u4e3a3\n\n-- \u4f4d\u53d6\u53cd\u8fd0\u7b97\nselect ~8; -- 8\u7684\u4e8c\u8fdb\u5236\u53d6\u53cd\u540e\u7ed3\u679c\u4e3a-9\uff08\u8865\u7801\u673a\u5236\uff09\n\n-- \u4f4d\u5de6\u79fb\u8fd0\u7b97\nselect 5&lt;&lt;1; -- 5\uff080101\uff09\u5de6\u79fb1\u4f4d\u4e3a10\uff081010\uff09\uff0c\u7ed3\u679c\u4e3a10\n\n-- \u4f4d\u53f3\u79fb\u8fd0\u7b97\nselect 5&gt;&gt;1; -- 5\uff080101\uff09\u53f3\u79fb1\u4f4d\u4e3a2\uff080010\uff09\uff0c\u7ed3\u679c\u4e3a2<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"OhXjB\">1.5 \u8fd0\u7b97\u7b26\u4f18\u5148\u7ea7<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"u72a64170\">MySQL\u4e2d\u8fd0\u7b97\u7b26\u7684\u4f18\u5148\u7ea7\u51b3\u5b9a\u4e86\u8fd0\u7b97\u7684\u6267\u884c\u987a\u5e8f\uff0c\u4f18\u5148\u7ea7\u9ad8\u7684\u5148\u6267\u884c\u3002\u82e5\u9700\u8c03\u6574\u987a\u5e8f\uff0c\u53ef\u4f7f\u7528\u62ec\u53f7<code>()<\/code>\u5305\u88f9\u8868\u8fbe\u5f0f\u3002\u4f18\u5148\u7ea7\u4ece\u9ad8\u5230\u4f4e\u5927\u81f4\u5982\u4e0b\uff08\u90e8\u5206\uff09\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u62ec\u53f7\uff08<code>()<\/code>\uff09<\/li>\n\n\n\n<li>\u4f4d\u53d6\u53cd\uff08<code>~<\/code>\uff09\u3001\u903b\u8f91\u975e\uff08<code>!<\/code>\uff09<\/li>\n\n\n\n<li>\u4e58\u6cd5\uff08<code>*<\/code>\uff09\u3001\u9664\u6cd5\uff08<code>\/<\/code>\uff09\u3001\u53d6\u4f59\uff08<code>%<\/code>\uff09<\/li>\n\n\n\n<li>\u52a0\u6cd5\uff08<code>+<\/code>\uff09\u3001\u51cf\u6cd5\uff08<code>-<\/code>\uff09<\/li>\n\n\n\n<li>\u4f4d\u5de6\u79fb\uff08<code>&lt;&lt;<\/code>\uff09\u3001\u4f4d\u53f3\u79fb\uff08<code>>><\/code>\uff09<\/li>\n\n\n\n<li>\u4f4d\u4e0e\uff08<code>&amp;<\/code>\uff09<\/li>\n\n\n\n<li>\u4f4d\u5f02\u6216\uff08<code>^<\/code>\uff09<\/li>\n\n\n\n<li>\u4f4d\u6216\uff08<code>|<\/code>\uff09<\/li>\n\n\n\n<li>\u6bd4\u8f83\u8fd0\u7b97\u7b26\uff08<code>=<\/code>, <code>><\/code>, <code>&lt;<\/code>\u7b49\uff09<\/li>\n\n\n\n<li>\u903b\u8f91\u4e0e\uff08<code>AND<\/code>\uff09<\/li>\n\n\n\n<li>\u903b\u8f91\u6216\uff08<code>OR<\/code>\uff09\u3001\u903b\u8f91\u5f02\u6216\uff08<code>XOR<\/code>\uff09<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"oSxZT\">1.6 \u65f6\u95f4\u51fd\u6570\u7684\u4f7f\u7528<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"u4e14dcbe\">\u65f6\u95f4\u51fd\u6570\u7528\u4e8e\u5904\u7406\u65e5\u671f\u548c\u65f6\u95f4\u7c7b\u578b\u7684\u6570\u636e\uff0c\u662f\u4e1a\u52a1\u4e2d\u8bb0\u5f55\u3001\u8ba1\u7b97\u65f6\u95f4\u7684\u6838\u5fc3\u5de5\u5177\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"ov3SM\">1.6.1 \u5e38\u7528\u65f6\u95f4\u51fd\u6570<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>CURDATE()<\/strong>\uff1a\u83b7\u53d6\u5f53\u524d\u65e5\u671f\uff08DATE\u7c7b\u578b\uff09\uff0c\u7b49\u6548\u4e8e<code>CURRENT_DATE()<\/code>\u6216<code>CURRENT_DATE<\/code><\/li>\n\n\n\n<li><strong>CURTIME()<\/strong>\uff1a\u83b7\u53d6\u5f53\u524d\u65f6\u95f4\uff08TIME\u7c7b\u578b\uff09\uff0c\u7b49\u6548\u4e8e<code>CURRENT_TIME()<\/code>\u6216<code>CURRENT_TIME<\/code><\/li>\n\n\n\n<li><strong>NOW()<\/strong>\uff1a\u83b7\u53d6\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4\uff08DATETIME\u7c7b\u578b\uff09\uff0c\u7b49\u6548\u4e8e<code>CURRENT_TIMESTAMP()<\/code>\u6216<code>CURRENT_TIMESTAMP<\/code><\/li>\n\n\n\n<li><strong>ADDDATE(date, INTERVAL expr unit)<\/strong>\uff1a\u7ed9\u65e5\u671f\u589e\u52a0\u6307\u5b9a\u65f6\u95f4\u95f4\u9694\uff08\u5982\u5929\u6570\u3001\u5468\u6570\uff09<\/li>\n\n\n\n<li><strong>ADDTIME(time, expr)<\/strong>\uff1a\u7ed9\u65f6\u95f4\u589e\u52a0\u6307\u5b9a\u65f6\u95f4\uff08\u5982\u5c0f\u65f6\u3001\u5206\u949f\uff09<\/li>\n\n\n\n<li><strong>UNIX_TIMESTAMP([date])<\/strong>\uff1a\u5c06\u65e5\u671f\u8f6c\u6362\u4e3aUnix\u65f6\u95f4\u6233\uff081970-01-01 00:00:00\u81f3\u4eca\u7684\u79d2\u6570\uff09\uff0c\u9ed8\u8ba4\u8fd4\u56de\u5f53\u524d\u65f6\u95f4\u6233<\/li>\n\n\n\n<li><strong>FROM_UNIXTIME(unix_timestamp[, format])<\/strong>\uff1a\u5c06Unix\u65f6\u95f4\u6233\u8f6c\u6362\u4e3a\u53ef\u8bfb\u65e5\u671f\uff0c\u652f\u6301\u81ea\u5b9a\u4e49\u683c\u5f0f<\/li>\n\n\n\n<li><strong>WEEK(date, [mode])<\/strong>\uff1a\u8ba1\u7b97\u65e5\u671f\u6240\u5728\u5e74\u4efd\u7684\u5468\u6570\uff08mode\u6307\u5b9a\u5468\u8d77\u59cb\u65e5\uff0c\u9ed8\u8ba4\u5468\u65e5\uff09<\/li>\n\n\n\n<li><strong>DATE_FORMAT(date, format)<\/strong>\uff1a\u6309\u81ea\u5b9a\u4e49\u683c\u5f0f\u683c\u5f0f\u5316\u65e5\u671f\uff08\u5982<code>%Y-%m-%d<\/code>\u8868\u793a\u201c\u5e74-\u6708-\u65e5\u201d\uff09<\/li>\n\n\n\n<li><strong>DATEDIFF(date1, date2)<\/strong>\uff1a\u8ba1\u7b97\u4e24\u4e2a\u65e5\u671f\u7684\u5929\u6570\u5dee\uff08date1 &#8211; date2\uff09<\/li>\n\n\n\n<li><strong>DATE_ADD(date, INTERVAL expr type)<\/strong>\uff1a\u4e0e<code>ADDDATE()<\/code>\u7c7b\u4f3c\uff0c\u652f\u6301\u66f4\u591a\u65f6\u95f4\u5355\u4f4d\uff08\u5982\u5c0f\u65f6\u3001\u6708\uff09<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"y0JM7\">1.6.2 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<pre id=\"d6ruh\" class=\"wp-block-code\"><code>-- \u83b7\u53d6\u5f53\u524d\u65e5\u671f\nselect CURDATE(); -- \u7ed3\u679c\u59822025-08-27\n\n-- \u83b7\u53d6\u5f53\u524d\u65f6\u95f4\nselect CURTIME(); -- \u7ed3\u679c\u598215:30:45\n\n-- \u83b7\u53d6\u5f53\u524d\u65e5\u671f\u65f6\u95f4\nselect NOW(); -- \u7ed3\u679c\u59822025-08-27 15:30:45\n\n-- \u65e5\u671f\u52a030\u5929\nselect ADDDATE('2010-01-01', 30); -- \u7ed3\u679c\u4e3a2010-01-31\n\n-- \u65f6\u95f4\u52a02\u5c0f\u65f630\u5206\u949f\nselect ADDTIME('2030-01-01 00:00:00', '02:30:00'); -- \u7ed3\u679c\u4e3a2030-01-01 02:30:00\n\n-- \u65e5\u671f\u8f6c\u65f6\u95f4\u6233\nselect UNIX_TIMESTAMP('2008-08-08 20:08:08'); -- \u7ed3\u679c\u4e3a1218125288\n\n-- \u5f53\u524d\u65f6\u95f4\u6233\nselect UNIX_TIMESTAMP(); -- \u7ed3\u679c\u4e3a\u5f53\u524dUnix\u65f6\u95f4\u6233\n\n-- \u65f6\u95f4\u6233\u8f6c\u65e5\u671f\nselect FROM_UNIXTIME(1447430881); -- \u7ed3\u679c\u4e3a\u5bf9\u5e94\u65e5\u671f\n\n-- \u65e5\u671f\u6240\u5728\u5468\u6570\nselect WEEK('2008-08-08'); -- \u7ed3\u679c\u4e3a32\uff082008\u5e74\u7b2c32\u5468\uff09\n\n-- \u683c\u5f0f\u5316\u65e5\u671f\nselect DATE_FORMAT('2008-08-08 20:08:08', '%Y-%M-%D'); -- \u7ed3\u679c\u4e3a2008-August-8th\n\n-- \u65e5\u671f\u5dee\nselect DATEDIFF('2030-06-07', '2030-01-01'); -- \u7ed3\u679c\u4e3a157\uff08\u76f8\u5dee157\u5929\uff09\n\n-- \u65e5\u671f\u52a0200\u5929\nselect DATE_ADD('2030-01-01', INTERVAL 200 DAY); -- \u7ed3\u679c\u4e3a2030-07-20<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"E1USy\">1.7 \u5b57\u7b26\u4e32\u51fd\u6570\u7684\u4f7f\u7528<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"ud31b03a7\">\u5b57\u7b26\u4e32\u51fd\u6570\u7528\u4e8e\u5904\u7406\u6587\u672c\u6570\u636e\uff0c\u5982\u62fc\u63a5\u3001\u622a\u53d6\u3001\u8f6c\u6362\u7b49\uff0c\u662f\u6570\u636e\u6e05\u6d17\u548c\u683c\u5f0f\u5316\u7684\u5e38\u7528\u5de5\u5177\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"iCniz\">1.7.1 \u5e38\u7528\u5b57\u7b26\u4e32\u51fd\u6570<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>CONCAT(str1, str2, &#8230;)<\/strong>\uff1a\u62fc\u63a5\u591a\u4e2a\u5b57\u7b26\u4e32<\/li>\n\n\n\n<li><strong>CHAR_LENGTH(str)<\/strong>\uff1a\u8ba1\u7b97\u5b57\u7b26\u4e32\u7684\u5b57\u7b26\u6570\uff08\u4e0e\u5b57\u8282\u6570\u65e0\u5173\uff09<\/li>\n\n\n\n<li><strong>INSERT(str, pos, len, newstr)<\/strong>\uff1a\u4ecestr\u7684pos\u4f4d\u7f6e\u5f00\u59cb\uff0c\u66ff\u6362len\u957f\u5ea6\u7684\u5b50\u4e32\u4e3anewstr\uff08pos\u4ece1\u5f00\u59cb\uff09<\/li>\n\n\n\n<li><strong>LOWER(str)<\/strong>\uff1a\u5c06\u5b57\u7b26\u4e32\u8f6c\u4e3a\u5c0f\u5199<\/li>\n\n\n\n<li><strong>UPPER(str)<\/strong>\uff1a\u5c06\u5b57\u7b26\u4e32\u8f6c\u4e3a\u5927\u5199<\/li>\n\n\n\n<li><strong>LEFT(str, len)<\/strong>\uff1a\u622a\u53d6str\u5de6\u4fa7\u7684len\u4e2a\u5b57\u7b26<\/li>\n\n\n\n<li><strong>RIGHT(str, len)<\/strong>\uff1a\u622a\u53d6str\u53f3\u4fa7\u7684len\u4e2a\u5b57\u7b26<\/li>\n\n\n\n<li><strong>REPEAT(str, count)<\/strong>\uff1a\u91cd\u590dstr\u6307\u5b9a\u6b21\u6570<\/li>\n\n\n\n<li><strong>SUBSTRING(str, start, len)<\/strong>\uff1a\u4ecestart\u4f4d\u7f6e\u622a\u53d6str\u7684len\u4e2a\u5b57\u7b26\uff08start\u53ef\u4e3a\u8d1f\u6570\uff0c\u4ece\u672b\u5c3e\u8ba1\u6570\uff09<\/li>\n\n\n\n<li><strong>LPAD(str, len, padstr)<\/strong>\uff1a\u5728str\u5de6\u4fa7\u586b\u5145padstr\uff0c\u76f4\u5230\u603b\u957f\u5ea6\u4e3alen<\/li>\n\n\n\n<li><strong>RPAD(str, len, padstr)<\/strong>\uff1a\u5728str\u53f3\u4fa7\u586b\u5145padstr\uff0c\u76f4\u5230\u603b\u957f\u5ea6\u4e3alen<\/li>\n\n\n\n<li><strong>LTRIM(str)<\/strong>\uff1a\u53bb\u9664str\u5de6\u4fa7\u7684\u7a7a\u683c<\/li>\n\n\n\n<li><strong>RTRIM(str)<\/strong>\uff1a\u53bb\u9664str\u53f3\u4fa7\u7684\u7a7a\u683c<\/li>\n\n\n\n<li><strong>TRIM(str)<\/strong>\uff1a\u53bb\u9664str\u4e24\u4fa7\u7684\u7a7a\u683c<\/li>\n\n\n\n<li><strong>REPLACE(str, from_str, to_str)<\/strong>\uff1a\u5c06str\u4e2d\u6240\u6709from_str\u66ff\u6362\u4e3ato_str<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"ugNSn\">1.7.2 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"uf8aa3dc8\">\u521b\u5efa\u6d4b\u8bd5\u8868\u7528\u4e8e\u9a8c\u8bc1\u5b57\u7b26\u4e32\u51fd\u6570\uff1a<\/p>\n\n\n\n<pre id=\"WV9zA\" class=\"wp-block-code\"><code>create table string_test(name varchar(10), class int);\ninsert into string_test values ('zhangsan', 1101), (' lisi ', 1102);<\/code><\/pre>\n\n\n\n<pre id=\"bIlBu\" class=\"wp-block-code\"><code>-- \u62fc\u63a5\u5b57\u7b26\u4e32\uff08\u524d\u540e\u52a0\u6a2a\u7ebf\uff09\nselect concat('-', name, '-') from string_test; -- \u7ed3\u679c\u4e3a-zhangsan-\u3001- lisi -\n\n-- \u62fc\u63a5\u5b57\u6bb5\u4e0e\u5e38\u91cf\nselect concat(name, '-', class) from string_test; -- \u7ed3\u679c\u4e3azhangsan-1101\u3001 lisi -1102\n\n-- \u8ba1\u7b97\u5b57\u7b26\u6570\nselect CHAR_LENGTH(name) from string_test; -- \u7ed3\u679c\u4e3a8\uff08zhangsan\uff09\u30015\uff08\u542b\u7a7a\u683c\u7684lisi\uff09\n\n-- \u66ff\u6362\u5b50\u4e32\uff08\u4ece\u7b2c3\u4f4d\u5f00\u59cb\uff0c\u66ff\u63622\u4e2a\u5b57\u7b26\u4e3atest\uff09\nselect INSERT(name, 3, 2, \"test\") from string_test; -- \u7ed3\u679c\u4e3azhtestgsan\u3001  tetisi \n\n-- \u5927\u5c0f\u5199\u8f6c\u6362\nselect LOWER(\"MySQL\"); -- \u7ed3\u679c\u4e3amysql\nselect UPPER(\"MySQL\"); -- \u7ed3\u679c\u4e3aMYSQL\n\n-- \u622a\u53d6\u5de6\u4fa7\/\u53f3\u4fa7\u5b57\u7b26\nselect LEFT('MySQL', 2); -- \u7ed3\u679c\u4e3aMy\nselect RIGHT('MySQL', 2); -- \u7ed3\u679c\u4e3aQL\n\n-- \u91cd\u590d\u5b57\u7b26\u4e32\nselect REPEAT('MySQL', 3); -- \u7ed3\u679c\u4e3aMySQLMySQLMySQL\n\n-- \u622a\u53d6\u5b50\u4e32\uff08\u4ece\u7b2c3\u4f4d\u5f00\u59cb\uff0c\u53d63\u4e2a\u5b57\u7b26\uff09\nselect SUBSTRING('MySQL', 3, 3); -- \u7ed3\u679c\u4e3aSQL\n\n-- \u5de6\u4fa7\/\u53f3\u4fa7\u586b\u5145\nselect LPAD('MySQL', 6, 'A'); -- \u7ed3\u679c\u4e3aAMySQL\uff08\u603b\u957f\u5ea66\uff09\nselect RPAD('MySQL', 8, 'B'); -- \u7ed3\u679c\u4e3aMySQLBBB\uff08\u603b\u957f\u5ea68\uff09\n\n-- \u53bb\u9664\u7a7a\u683c\nselect concat('-', LTRIM(' MySQL '), '-'); -- \u7ed3\u679c\u4e3a-MySQL -\uff08\u53bb\u5de6\u4fa7\u7a7a\u683c\uff09\nselect concat('-', RTRIM(' MySQL '), '-'); -- \u7ed3\u679c\u4e3a- MySQL-\uff08\u53bb\u53f3\u4fa7\u7a7a\u683c\uff09\nselect concat('-', TRIM(' MySQL '), '-'); -- \u7ed3\u679c\u4e3a-MySQL-\uff08\u53bb\u4e24\u4fa7\u7a7a\u683c\uff09\n\n-- \u66ff\u6362\u5b50\u4e32\nselect REPLACE('MySQL', 'My', 'Postgre'); -- \u7ed3\u679c\u4e3aPostgreSQL<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"C0piC\">1.8 \u6570\u503c\u51fd\u6570\u7684\u4f7f\u7528<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"ua3883b67\">\u6570\u503c\u51fd\u6570\u7528\u4e8e\u5904\u7406\u6570\u503c\u578b\u6570\u636e\uff0c\u5982\u53d6\u7edd\u5bf9\u503c\u3001\u56db\u820d\u4e94\u5165\u7b49\uff0c\u9002\u7528\u4e8e\u6570\u636e\u8ba1\u7b97\u548c\u7edf\u8ba1\u573a\u666f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"hegBD\">1.8.1 \u5e38\u7528\u6570\u503c\u51fd\u6570<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>ABS(x)<\/strong>\uff1a\u8fd4\u56dex\u7684\u7edd\u5bf9\u503c<\/li>\n\n\n\n<li><strong>MOD(x, y)<\/strong>\uff1a\u8fd4\u56dex\u9664\u4ee5y\u7684\u4f59\u6570\uff08\u4e0e<code>x%y<\/code>\u7b49\u6548\uff09<\/li>\n\n\n\n<li><strong>RAND()<\/strong>\uff1a\u8fd4\u56de0~1\u4e4b\u95f4\u7684\u968f\u673a\u6d6e\u70b9\u6570<\/li>\n\n\n\n<li><strong>CEILING(x)<\/strong> \u6216 <strong>CEIL(x)<\/strong>\uff1a\u5411\u4e0a\u53d6\u6574\uff08\u8fd4\u56de\u5927\u4e8e\u7b49\u4e8ex\u7684\u6700\u5c0f\u6574\u6570\uff09<\/li>\n\n\n\n<li><strong>FLOOR(x)<\/strong>\uff1a\u5411\u4e0b\u53d6\u6574\uff08\u8fd4\u56de\u5c0f\u4e8e\u7b49\u4e8ex\u7684\u6700\u5927\u6574\u6570\uff09<\/li>\n\n\n\n<li><strong>ROUND(x, d)<\/strong>\uff1a\u5c06x\u56db\u820d\u4e94\u5165\u4fdd\u7559d\u4f4d\u5c0f\u6570\uff08d\u9ed8\u8ba40\uff09<\/li>\n\n\n\n<li><strong>TRUNCATE(x, d)<\/strong>\uff1a\u622a\u65adx\u4fdd\u7559d\u4f4d\u5c0f\u6570\uff08\u76f4\u63a5\u53bb\u9664\u591a\u4f59\u5c0f\u6570\u4f4d\uff09<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"W25wa\">1.8.2 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<pre id=\"PT7ap\" class=\"wp-block-code\"><code>-- \u7edd\u5bf9\u503c\nselect ABS(-10); -- \u7ed3\u679c\u4e3a10\nselect ABS(10.5); -- \u7ed3\u679c\u4e3a10.5\n\n-- \u53d6\u4f59\nselect MOD(10, 3); -- \u7ed3\u679c\u4e3a1\nselect MOD(10.5, 3); -- \u7ed3\u679c\u4e3a1.5\n\n-- \u968f\u673a\u6570\nselect RAND(); -- \u7ed3\u679c\u4e3a0~1\u7684\u968f\u673a\u6570\uff08\u59820.3827160493334249\uff09\n\n-- \u5411\u4e0a\u53d6\u6574\nselect CEILING(1.1); -- \u7ed3\u679c\u4e3a2\nselect CEIL(1.9); -- \u7ed3\u679c\u4e3a2\n\n-- \u5411\u4e0b\u53d6\u6574\nselect FLOOR(1.1); -- \u7ed3\u679c\u4e3a1\nselect FLOOR(1.9); -- \u7ed3\u679c\u4e3a1\n\n-- \u56db\u820d\u4e94\u5165\uff08\u4fdd\u75592\u4f4d\u5c0f\u6570\uff09\nselect ROUND(10.565, 2); -- \u7ed3\u679c\u4e3a10.57\nselect ROUND(10.564, 2); -- \u7ed3\u679c\u4e3a10.56\n\n-- \u622a\u65ad\uff08\u4fdd\u75592\u4f4d\u5c0f\u6570\uff09\nselect TRUNCATE(10.567, 2); -- \u7ed3\u679c\u4e3a10.56\nselect TRUNCATE(10.564, 2); -- \u7ed3\u679c\u4e3a10.56<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"hDoRH\">1.9 JSON\u51fd\u6570\u7684\u4f7f\u7528<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"u216a93b8\">JSON\u51fd\u6570\u7528\u4e8e\u5904\u7406MySQL\u4e2d\u7684JSON\u7c7b\u578b\u6570\u636e\uff0c\u652f\u6301\u521b\u5efa\u3001\u89e3\u6790\u3001\u4fee\u6539JSON\u683c\u5f0f\u6570\u636e\uff0c\u9002\u7528\u4e8e\u7075\u6d3b\u5b58\u50a8\u573a\u666f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"PSgeF\">1.9.1 \u5e38\u7528JSON\u51fd\u6570<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>JSON_OBJECT(key1, val1, &#8230;)<\/strong>\uff1a\u521b\u5efaJSON\u5bf9\u8c61<\/li>\n\n\n\n<li><strong>JSON_ARRAY(val1, val2, &#8230;)<\/strong>\uff1a\u521b\u5efaJSON\u6570\u7ec4<\/li>\n\n\n\n<li><strong>JSON_MERGE(json1, json2, &#8230;)<\/strong>\uff1a\u5408\u5e76\u591a\u4e2aJSON\u5bf9\u8c61\/\u6570\u7ec4\uff08\u540c\u952e\u540e\u503c\u8986\u76d6\u524d\u503c\uff09<\/li>\n\n\n\n<li><strong>JSON_EXTRACT(json, path)<\/strong>\uff1a\u4eceJSON\u4e2d\u63d0\u53d6path\u8def\u5f84\u7684\u503c\uff08\u53ef\u7b80\u5199\u4e3a<code>json->path<\/code>\uff09<\/li>\n\n\n\n<li><strong>JSON_SEARCH(json, mode, str)<\/strong>\uff1a\u5728JSON\u4e2d\u641c\u7d22str\uff0c\u8fd4\u56de\u8def\u5f84\uff08mode\u4e3a<code>one<\/code>\u6216<code>all<\/code>\uff09<\/li>\n\n\n\n<li><strong>JSON_INSERT(json, path, val)<\/strong>\uff1a\u5411JSON\u63d2\u5165val\uff08\u4ec5path\u4e0d\u5b58\u5728\u65f6\u751f\u6548\uff09<\/li>\n\n\n\n<li><strong>JSON_SET(json, path, val)<\/strong>\uff1a\u66f4\u65b0\u6216\u63d2\u5165val\uff08\u65e0\u8bbapath\u662f\u5426\u5b58\u5728\uff09<\/li>\n\n\n\n<li><strong>JSON_REPLACE(json, path, val)<\/strong>\uff1a\u66ff\u6362JSON\u4e2dpath\u7684\u503c\uff08\u4ec5path\u5b58\u5728\u65f6\u751f\u6548\uff09<\/li>\n\n\n\n<li><strong>JSON_REMOVE(json, path)<\/strong>\uff1a\u5220\u9664JSON\u4e2dpath\u7684\u503c<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"aW4ON\">1.9.2 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<pre id=\"UhVxl\" class=\"wp-block-code\"><code>-- \u521b\u5efaJSON\u5bf9\u8c61\nselect JSON_OBJECT('name', 'John', 'age', 30); -- \u7ed3\u679c\u4e3a{\"name\": \"John\", \"age\": 30}\n\n-- \u521b\u5efa\u542bJSON\u5b57\u6bb5\u7684\u8868\ncreate table json_test(id int, a json);\n\n-- \u63d2\u5165JSON\u5bf9\u8c61\u6570\u636e\ninsert into json_test values (1, JSON_OBJECT('name', 'John', 'age', 30));\n\n-- \u63d2\u5165JSON\u6570\u7ec4\u6570\u636e\ninsert into json_test values (2, JSON_ARRAY('apple', 'banana', 'orange'));\n\n-- \u67e5\u8be2\u5168\u8868\u6570\u636e\nselect * from json_test;\n\n-- \u5408\u5e76JSON\u5bf9\u8c61\nselect JSON_MERGE(\n  JSON_OBJECT('name', 'John', 'age', 30),\n  JSON_OBJECT('address', '123 Main St')\n); -- \u7ed3\u679c\u4e3a{\"name\": \"John\", \"age\": 30, \"address\": \"123 Main St\"}\n\n-- \u63d0\u53d6JSON\u503c\uff08\u83b7\u53d6name\u5b57\u6bb5\uff09\nselect JSON_EXTRACT(a, '$.name') from json_test where id=1; -- \u7ed3\u679c\u4e3a\"John\"\n\n-- \u641c\u7d22JSON\u4e2d\u7684\u503c\uff08\u67e5\u627eJohn\u7684\u8def\u5f84\uff09\nselect JSON_SEARCH(a, 'one', 'John') from json_test where id=1; -- \u7ed3\u679c\u4e3a\"$.name\"\n\n-- \u63d2\u5165\u65b0\u952e\u503c\uff08\u6dfb\u52a0class\u5b57\u6bb5\uff09\nselect JSON_INSERT(a, '$.class', 'class1') from json_test where id=1;\n\n-- \u66f4\u65b0\u5df2\u6709\u952e\u503c\uff08\u4fee\u6539name\u4e3aJane\uff09\nselect JSON_SET(a, '$.name', 'Jane') from json_test where id=1;\n\n-- \u66ff\u6362\u5df2\u6709\u952e\u503c\uff08\u4fee\u6539age\u4e3a31\uff09\nselect JSON_REPLACE(a, '$.age', 31) from json_test where id=1;\n\n-- \u5220\u9664\u952e\u503c\uff08\u5220\u9664age\u5b57\u6bb5\uff09\nselect JSON_REMOVE(a, '$.age') from json_test where id=1;<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"jdjt0\">1.10 \u5176\u4ed6\u5e38\u7528\u51fd\u6570<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"p9wR0\">1.10.1 \u6761\u4ef6\u5224\u65ad\u51fd\u6570<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>IF(expr, val1, val2)<\/strong>\uff1a\u82e5expr\u4e3a\u771f\uff0c\u8fd4\u56deval1\uff0c\u5426\u5219\u8fd4\u56deval2<\/li>\n\n\n\n<li><strong>IFNULL(val1, val2)<\/strong>\uff1a\u82e5val1\u4e0d\u4e3aNULL\uff0c\u8fd4\u56deval1\uff0c\u5426\u5219\u8fd4\u56deval2<\/li>\n\n\n\n<li><strong>CASE<\/strong>\uff1a\u591a\u6761\u4ef6\u5206\u652f\u5224\u65ad\uff0c\u8bed\u6cd5\uff1a<\/li>\n<\/ul>\n\n\n\n<pre id=\"spGDd\" class=\"wp-block-code\"><code>CASE \n  WHEN cond1 THEN val1 \n  WHEN cond2 THEN val2 \n  ELSE val3 \nEND<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"luyhp\">1.10.2 \u7cfb\u7edf\u76f8\u5173\u51fd\u6570<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>VERSION()<\/strong>\uff1a\u8fd4\u56deMySQL\u670d\u52a1\u5668\u7248\u672c<\/li>\n\n\n\n<li><strong>USER()<\/strong>\uff1a\u8fd4\u56de\u5f53\u524d\u767b\u5f55\u7528\u6237\u540d\uff08\u683c\u5f0f\uff1auser@host\uff09<\/li>\n\n\n\n<li><strong>CHARSET(str)<\/strong>\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32str\u7684\u5b57\u7b26\u96c6<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"UbSfy\">1.10.3 IP\u4e0e\u6570\u5b57\u8f6c\u6362\u51fd\u6570<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>INET_ATON(ip)<\/strong>\uff1a\u5c06IPv4\u5730\u5740\u8f6c\u6362\u4e3a\u957f\u6574\u578b\u6570\u503c<\/li>\n\n\n\n<li><strong>INET_NTOA(num)<\/strong>\uff1a\u5c06\u957f\u6574\u578b\u6570\u503c\u8f6c\u6362\u4e3aIPv4\u5730\u5740<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"WBFyq\">1.10.4 \u5b9e\u9a8c\u6f14\u793a<\/h3>\n\n\n\n<pre id=\"Gq51B\" class=\"wp-block-code\"><code>-- IF\u51fd\u6570\uff08\u5224\u65ad2&gt;1\u662f\u5426\u6210\u7acb\uff09\nselect IF(2&gt;1, 'true', 'false'); -- \u7ed3\u679c\u4e3atrue\n\n-- IFNULL\u51fd\u6570\uff08\u5904\u7406NULL\u503c\uff09\nselect IFNULL(null, 'is null'); -- \u7ed3\u679c\u4e3ais null\n\n-- CASE\u51fd\u6570\uff08\u591a\u6761\u4ef6\u5224\u65ad\uff09\nselect case 1\n  when 1 then '\u7b49\u4e8e1'\n  when 2 then '\u7b49\u4e8e2'\n  else '\u4e0d\u662f1\u4e5f\u4e0d\u662f2'\nend; -- \u7ed3\u679c\u4e3a\u7b49\u4e8e1\n\n-- \u7cfb\u7edf\u51fd\u6570\nselect VERSION(); -- \u7ed3\u679c\u59828.0.36\nselect USER(); -- \u7ed3\u679c\u5982root@localhost\nselect CHARSET('\u6d4b\u8bd5'); -- \u7ed3\u679c\u5982utf8mb4\n\n-- IP\u4e0e\u6570\u5b57\u8f6c\u6362\nselect INET_ATON('192.168.1.2'); -- \u7ed3\u679c\u4e3a3232235778\nselect INET_NTOA(3232235778); -- \u7ed3\u679c\u4e3a192.168.1.2<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"RYaCn\">1.11 \u6848\u4f8b\uff1a\u5546\u54c1\u5e93\u5b58\u8868\u64cd\u4f5c<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"nVr85\">1.11.1 \u521b\u5efa\u8868\u5e76\u63d2\u5165\u6570\u636e<\/h3>\n\n\n\n<pre id=\"YCn3t\" class=\"wp-block-code\"><code>-- \u521b\u5efa\u5546\u54c1\u5e93\u5b58\u8868\nCREATE TABLE product_inventory (\n  id INT NOT NULL AUTO_INCREMENT COMMENT '\u884cID',\n  product_number VARCHAR(50) NOT NULL COMMENT '\u5546\u54c1\u7f16\u53f7',\n  product_name VARCHAR(255) NOT NULL COMMENT '\u5546\u54c1\u540d\u79f0',\n  manufacturer VARCHAR(255) NOT NULL COMMENT '\u5546\u54c1\u5382\u5546',\n  production_date DATE NOT NULL COMMENT '\u751f\u4ea7\u65e5\u671f',\n  shelf_life INT NOT NULL COMMENT '\u4fdd\u8d28\u671f\uff08\u5929\uff09',\n  price DECIMAL(10, 2) NOT NULL COMMENT '\u5355\u4ef7',\n  stock INT NOT NULL COMMENT '\u5e93\u5b58\u6570\u91cf',\n  PRIMARY KEY (id),\n  UNIQUE KEY (product_number) -- \u5546\u54c1\u7f16\u53f7\u552f\u4e00\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='\u5546\u54c1\u5e93\u5b58\u8868';\n\n-- \u63d2\u5165\u6d4b\u8bd5\u6570\u636e\nINSERT INTO product_inventory (product_number, product_name, manufacturer, production_date, shelf_life, price, stock)\nVALUES \n  ('P10001', '\u53ef\u53e3\u53ef\u4e50', '\u53ef\u53e3\u53ef\u4e50\u516c\u53f8', '2021-07-01', 365, 3.00, 1000),\n  ('P10002', '\u738b\u8001\u5409', '\u5e7f\u5dde\u738b\u8001\u5409\u751f\u7269\u79d1\u6280\u6709\u9650\u516c\u53f8', '2021-06-01', 360, 2.50, 800);<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"Wl4WD\">1.11.2 \u4e1a\u52a1\u67e5\u8be2\u793a\u4f8b<\/h3>\n\n\n\n<pre id=\"fz9vC\" class=\"wp-block-code\"><code>-- \u62fc\u63a5\u5546\u54c1\u540d\u79f0\u4e0e\u5382\u5546\nselect concat(product_name, ' - ', manufacturer) as product_info from product_inventory;\n-- \u7ed3\u679c\uff1a\u53ef\u53e3\u53ef\u4e50 - \u53ef\u53e3\u53ef\u4e50\u516c\u53f8\u3001\u738b\u8001\u5409 - \u5e7f\u5dde\u738b\u8001\u5409\u751f\u7269\u79d1\u6280\u6709\u9650\u516c\u53f8\n\n-- \u8ba1\u7b97\u603b\u5e93\u5b58\u4ef7\u503c\uff08\u5355\u4ef7\u00d7\u5e93\u5b58\u6c42\u548c\uff09\nselect sum(price * stock) as total_value from product_inventory;\n-- \u7ed3\u679c\uff1a3.00\u00d71000 + 2.50\u00d7800 = 5000.00\n\n-- \u8ba1\u7b97\u8fc7\u671f\u65e5\u671f\uff08\u751f\u4ea7\u65e5\u671f+\u4fdd\u8d28\u671f\uff09\nselect product_name, \n  date_add(production_date, interval shelf_life day) as expiration_date \nfrom product_inventory;\n-- \u7ed3\u679c\uff1a\u53ef\u53e3\u53ef\u4e50\u21922022-07-01\uff0c\u738b\u8001\u5409\u21922022-05-27<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"wyul4\">1.12 \u7ae0\u672b\u603b\u7ed3<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td>\u77e5\u8bc6\u70b9<\/td><td>\u9700\u8981\u638c\u63e1\u7684\u5185\u5bb9<\/td><\/tr><tr><td>\u7b97\u672f\u8fd0\u7b97\u7b26<\/td><td>\u52a0\u51cf\u4e58\u9664\u3001\u53d6\u4f59<\/td><\/tr><tr><td>\u6bd4\u8f83\u8fd0\u7b97\u7b26<\/td><td><code>=<\/code>\u3001<code>&lt;&gt;<\/code>\u3001<code>&gt;<\/code>\u3001<code>&lt;<\/code>\u3001<code>&gt;=<\/code>\u3001<code>&lt;=<\/code>\u3001<code>BETWEEN<\/code>\u3001<code>IN<\/code>\u3001<code>IS NULL<\/code><\/td><\/tr><tr><td>\u903b\u8f91\u8fd0\u7b97\u7b26<\/td><td><code>NOT<\/code>\u6216<code>!<\/code>\u3001<code>AND<\/code>\u3001<code>OR<\/code>\u3001<code>XOR<\/code><\/td><\/tr><tr><td>\u4f4d\u8fd0\u7b97\u7b26<\/td><td><code>&amp;<\/code>\u3001<code>|<\/code>\u3001<code>^<\/code>\u3001<code>~<\/code>\u3001<code>&lt;&lt;<\/code>\u3001<code>&gt;&gt;<\/code><\/td><\/tr><tr><td>\u8fd0\u7b97\u7b26\u4f18\u5148\u7ea7<\/td><td>\u4f18\u5148\u7ea7\u8868\u683c\u3001\u5efa\u8bae\u7ed9\u9700\u8981\u505a\u8fd0\u7b97\u7684\u8868\u8fbe\u5f0f\u52a0\u4e0a\u62ec\u53f7<\/td><\/tr><tr><td>\u65f6\u95f4\u51fd\u6570<\/td><td><code>CURDATE()<\/code>\u3001<code>CURTIME()<\/code>\u3001<code>NOW()<\/code>\u3001<code>ADDDATE()<\/code>\u3001<code>ADDTIME()<\/code>\u3001<code>UNIX_TIMESTAMP()<\/code>\u3001<code>FROM_UNIXTIME()<\/code>\u3001<code>WEEK()<\/code>\u3001<code>DATE_FORMAT()<\/code>\u3001<code>DATEDIFF()<\/code>\u3001<code>DATE_ADD()<\/code><\/td><\/tr><tr><td>\u5b57\u7b26\u4e32\u51fd\u6570<\/td><td><code>CONCAT()<\/code>\u3001<code>CHAR_LENGTH()<\/code>\u3001<code>INSERT()<\/code>\u3001<code>LOWER()<\/code>\u3001<code>UPPER()<\/code>\u3001<code>LEFT()<\/code>\u3001<code>RIGHT()<\/code>\u3001<code>REPEAT()<\/code>\u3001<code>SUBSTRING()<\/code>\u3001<code>LPAD()<\/code>\u3001<code>RPAD()<\/code>\u3001<code>LTRIM()<\/code>\u3001<code>RTRIM()<\/code>\u3001<code>TRIM()<\/code>\u3001<code>REPLACE()<\/code><\/td><\/tr><tr><td>\u6570\u503c\u51fd\u6570<\/td><td><code>ABS()<\/code>\u3001<code>MOD()<\/code>\u3001<code>RAND()<\/code>\u3001<code>CEILING()<\/code>\u3001<code>FLOOR()<\/code>\u3001<code>ROUND()<\/code>\u3001<code>TRUNCATE()<\/code><\/td><\/tr><tr><td>JSON\u51fd\u6570<\/td><td><code>JSON_OBJECT()<\/code>\u3001<code>JSON_ARRAY()<\/code>\u3001<code>JSON_MERGE()<\/code>\u3001<code>JSON_EXTRACT()<\/code>\u3001<code>JSON_SEARCH()<\/code>\u3001<code>JSON_INSERT()<\/code>\u3001<code>JSON_SET()<\/code>\u3001<code>JSON_REPLACE()<\/code>\u3001<code>JSON_REMOVE()<\/code><\/td><\/tr><tr><td>\u5176\u4ed6\u51fd\u6570<\/td><td><code>IF()<\/code>\u3001<code>IFNULL()<\/code>\u3001<code>CASE<\/code>\u3001<code>VERSION()<\/code>\u3001<code>USER()<\/code>\u3001<code>CHARSET()<\/code>\u3001<code>INET_ATON()<\/code>\u3001<code>INET_NTOA()<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"uae84b0e6\">\u672c\u6587\u56f4\u7ed5MySQL\u7684\u8fd0\u7b97\u4e0e\u51fd\u6570\u5c55\u5f00\uff0c\u6db5\u76d6\u4e86\u7b97\u672f\u3001\u6bd4\u8f83\u3001\u903b\u8f91\u3001\u4f4d\u8fd0\u7b97\u7b26\u7684\u7528\u6cd5\uff0c\u4ee5\u53ca\u65f6\u95f4\u3001\u5b57\u7b26\u4e32\u3001\u6570\u503c\u3001JSON\u7b49\u5e38\u7528\u51fd\u6570\u7684\u5b9e\u8df5\u3002\u8fd9\u4e9b\u5de5\u5177\u662f\u5904\u7406\u6570\u636e\u8ba1\u7b97\u3001\u6761\u4ef6\u8fc7\u6ee4\u3001\u683c\u5f0f\u8f6c\u6362\u7684\u6838\u5fc3\u80fd\u529b\uff0c\u9700\u7ed3\u5408\u4e1a\u52a1\u573a\u666f\u7075\u6d3b\u8fd0\u7528\u3002\u5b9e\u9645\u5de5\u4f5c\u4e2d\uff0c\u5e94\u6ce8\u610f\u8fd0\u7b97\u7b26\u4f18\u5148\u7ea7\u5bf9\u7ed3\u679c\u7684\u5f71\u54cd\uff0c\u4ee5\u53ca\u51fd\u6570\u5728\u6027\u80fd\u4f18\u5316\u4e2d\u7684\u5408\u7406\u4f7f\u7528\uff08\u5982\u907f\u514d\u5728WHERE\u5b50\u53e5\u4e2d\u5bf9\u5b57\u6bb5\u4f7f\u7528\u51fd\u6570\uff0c\u4ee5\u514d\u7d22\u5f15\u5931\u6548\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u672c\u6587\u56f4\u7ed5MySQL\u7684\u8fd0\u7b97\u4e0e\u51fd\u6570\u5c55\u5f00\uff0c\u6db5\u76d6\u4e86\u7b97\u672f\u3001\u6bd4\u8f83\u3001\u903b\u8f91\u3001\u4f4d\u8fd0\u7b97\u7b26\u7684\u7528\u6cd5\uff0c\u4ee5\u53ca\u65f6\u95f4\u3001\u5b57\u7b26\u4e32\u3001\u6570\u503c\u3001JSON\u7b49\u5e38\u7528\u51fd\u6570\u7684\u5b9e\u8df5\u3002<\/p>\n","protected":false},"author":1,"featured_media":206,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[16],"class_list":["post-205","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mysql","tag-mysql"],"_links":{"self":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/205","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=205"}],"version-history":[{"count":1,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/205\/revisions"}],"predecessor-version":[{"id":207,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/205\/revisions\/207"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/media\/206"}],"wp:attachment":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=205"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=205"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}