{"id":104,"date":"2021-01-05T16:06:32","date_gmt":"2021-01-05T08:06:32","guid":{"rendered":"https:\/\/www.52dixiaowo.com\/database\/?p=104"},"modified":"2021-09-09T16:20:26","modified_gmt":"2021-09-09T08:20:26","slug":"%e4%ba%8b%e5%8a%a1","status":"publish","type":"post","link":"https:\/\/www.52dixiaowo.com\/db\/post-104.html","title":{"rendered":"SQL \u4e8b\u52a1"},"content":{"rendered":"\n

\u6982\u5ff5\uff1a\u4e8b\u52a1\u662f\u591a\u4e2a sql \u64cd\u4f5c\u7684\u96c6\u5408\uff0c\u8fd9\u4e9b\u64cd\u4f5c\u8981\u4e48\u540c\u65f6\u6210\u529f\uff0c\u8981\u4e48\u540c\u65f6\u5931\u8d25\u3002<\/p>\n\n\n\n

1.\u4e8b\u52a1\u7684\u64cd\u4f5c<\/h4>\n\n\n\n

1.\u5f00\u542f\u4e8b\u52a1<\/h5>\n\n\n\n

\u53ea\u6709\u5f00\u542f\u4e86\u4e8b\u52a1\uff0c\u624d\u80fd\u591f\u8fdb\u884c\u56de\u6eda\u7b49\u64cd\u4f5c<\/p>\n\n\n\n

start transaction;<\/code><\/pre>\n\n\n\n
2.\u56de\u6eda<\/h5>\n\n\n\n
\u64cd\u4f5c\u5931\u8d25\uff0c\u56de\u5230\u5f00\u542f\u4e8b\u52a1\u7684\u5730\u65b9<\/p>\n\n\n\n
rollback;<\/code><\/pre>\n\n\n\n
3.\u63d0\u4ea4<\/h5>\n\n\n\n
\u64cd\u4f5c\u6210\u529f\uff0c\u6570\u636e\u63d0\u4ea4<\/p>\n\n\n\n
commit;<\/code><\/pre>\n\n\n\n
4. mysql \u7684\u4e8b\u52a1\u6ce8\u610f\u4e8b\u9879<\/h5>\n\n\n\n
mysql \u9ed8\u8ba4\u6bcf\u6761\u8bed\u53e5\u90fd\u662f\u4e00\u4e2a\u4e8b\u52a1\uff0c\u4f1a\u81ea\u52a8\u63d0\u4ea4\uff08Oracle\u9ed8\u8ba4\u662f\u624b\u52a8\u63d0\u4ea4\uff09<\/p>\n\n\n\n
mysql \u624b\u52a8\u5f00\u542f\u4e8b\u52a1\u540e\uff0c\u5fc5\u987b\u624b\u52a8\u63d0\u4ea4\uff0c\u5426\u5219\u81ea\u52a8\u56de\u6eda<\/p>\n\n\n\n
\u67e5\u770b\u4e8b\u52a1\u7684\u9ed8\u8ba4\u63d0\u4ea4\u65b9\u5f0f<\/p>\n\n\n\n
SELECT @@autocommit;<\/code><\/pre>\n\n\n\n
\u4fee\u6539\u4e8b\u52a1\u7684\u9ed8\u8ba4\u63d0\u4ea4\u65b9\u5f0f \uff08 1 \u4ee3\u8868\u81ea\u52a8\u63d0\u4ea4 0 \u4ee3\u8868\u624b\u52a8\u63d0\u4ea4\uff09<\/p>\n\n\n\n
set @@autocommit = 0;<\/code><\/pre>\n\n\n\n
2.\u4e8b\u52a1\u7684\u56db\u5927\u7279\u5f81<\/h4>\n\n\n\n
1.\u539f\u5b50\u6027<\/h5>\n\n\n\n
\u662f\u4e0d\u53ef\u5206\u5272\u7684\u6700\u5c0f\u64cd\u4f5c\u5355\u4f4d\uff0c\u8981\u4e48\u540c\u65f6\u6210\u529f\uff0c\u8981\u4e48\u540c\u65f6\u5931\u8d25\u3002<\/p>\n\n\n\n
2.\u6301\u4e45\u6027<\/h5>\n\n\n\n
\u5f53\u4e8b\u52a1\u63d0\u4ea4\u6216\u56de\u6eda\u540e\uff0c\u6570\u636e\u5e93\u4f1a\u6301\u4e45\u5316\u7684\u4fdd\u5b58\u6570\u636e\u3002<\/p>\n\n\n\n
\uff08\u5982\u679c\u672a\u63d0\u4ea4\u6216\u56de\u6eda\uff0c\u53ea\u662f\u4e34\u65f6\u6570\u636e\uff09<\/p>\n\n\n\n
3.\u9694\u79bb\u6027<\/h5>\n\n\n\n
\u591a\u4e2a\u4e8b\u52a1\u4e4b\u95f4\u3002\u76f8\u4e92\u72ec\u7acb\u3002\uff08\u5b9e\u9645\u4f1a\u76f8\u4e92\u5f71\u54cd\uff0c\u5b9e\u73b0\u72ec\u7acb\u8981\u624b\u52a8\u9694\u79bb\uff09<\/p>\n\n\n\n
4.\u4e00\u81f4\u6027<\/h5>\n\n\n\n
\u4e8b\u52a1\u64cd\u4f5c\u524d\u540e\uff0c\u6570\u636e\u603b\u91cf\u4e0d\u53d8<\/p>\n\n\n\n
\uff08\u6bd4\u5982 a-50, b+50 \uff0c\u4f46 a+b \u7684\u603b\u91cf\u4ecd\u7136\u662f\u4e00\u81f4\u7684\uff09<\/p>\n\n\n\n
3.\u4e8b\u52a1\u7684\u9694\u79bb\u4e0e\u9694\u79bb\u7ea7\u522b<\/h4>\n\n\n\n
\u6982\u5ff5\uff1a\u591a\u4e2a\u4e8b\u52a1\u4e4b\u95f4\u662f\u9694\u79bb\u7684\uff0c\u4f46\u5982\u679c\u591a\u4e2a\u4e8b\u52a1\u64cd\u4f5c\u540c\u4e00\u6279\u6570\u636e\uff0c\u4f1a\u662f\u76f8\u4e92\u5f71\u54cd\u7684\uff0c\u800c\u4e8b\u52a1\u9694\u79bb\u5c31\u662f\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e9b\u95ee\u9898\u3002\uff08\u9694\u79bb\u7ea7\u522b\u8d8a\u9ad8\uff0c\u6548\u7387\u8d8a\u4f4e\uff09<\/p>\n\n\n\n
\u4e8b\u52a1\u5b58\u5728\u7684\u95ee\u9898\u901a\u5e38\u6709\u4ee5\u4e0b 3 \u79cd<\/p>\n\n\n\n
  1. \u810f\u8bfb\uff1a\u4e00\u4e2a\u4e8b\u52a1\uff0c\u8bfb\u53d6\u5230\u53e6\u4e00\u4e2a\u4e8b\u52a1\u8fd8\u672a\u63d0\u4ea4\u7684\u4e8b\u52a1\u6570\u636e\uff08\u6570\u636e\u6b3a\u9a97\uff09<\/li>
  2. \u4e0d\u53ef\u91cd\u590d\u8bfb\uff08\u865a\u8bfb\uff09\uff1a\u5728\u540c\u4e00\u4e2a\u4e8b\u52a1\u4e2d\uff0c\u4e24\u6b21\u8bfb\u53d6\u5230\u7684\u6570\u636e\u4e0d\u4e00\u6837\uff08\u6570\u636e\u53d8\u5316)<\/li>
  3. \u5e7b\u8bfb\uff1a\u4e00\u4e2a\u4e8b\u52a1\u64cd\u4f5c(DML)\u6570\u636e\u8868\u4e2d\u7684\u6240\u6709\u6570\u636e\uff0c\u53e6\u4e00\u4e2a\u4e8b\u52a1\u6dfb\u52a0\u4e86\u4e00\u6761\u6570\u636e\uff0c\u5219\u7b2c\u4e00\u4e2a\u4e8b\u52a1\u67e5\u8be2\u4e0d\u5230\u81ea\u5df1\u7684\u4fee\u6539\uff08\u4f1a\u9020\u6210\u64cd\u4f5c\u5931\u6548\uff09<\/li><\/ol>\n\n\n\n
    \u67e5\u8be2\u9ed8\u8ba4\u7684\u9694\u79bb\u7ea7\u522b<\/p>\n\n\n\n
    select @@tx_isolation;<\/code><\/pre>\n\n\n\n
    \u8bbe\u7f6e\u6570\u636e\u5e93\u7684\u9694\u79bb\u7ea7\u522b<\/p>\n\n\n\n
    set global transaction isolation level  \u7ea7\u522b\u5b57\u7b26\u4e32;<\/code><\/pre>\n\n\n\n
    1.read uncommitted \uff1a\u8bfb\u672a\u63d0\u4ea4<\/h5>\n\n\n\n
    \u4ea7\u751f\u7684\u95ee\u9898\uff1a\u810f\u8bfb\uff0c\u4e0d\u53ef\u91cd\u590d\u8bfb\uff0c\u5e7b\u8bfb<\/p>\n\n\n\n
    2.read committed\uff1a\u8bfb\u5df2\u63d0\u4ea4\uff08oracle \u9ed8\u8ba4\uff09<\/h5>\n\n\n\n
    \u4ea7\u751f\u7684\u95ee\u9898\uff1a\u4e0d\u53ef\u91cd\u590d\u8bfb\uff0c\u5e7b\u8bfb<\/p>\n\n\n\n
    3.repeatable read\uff1a\u53ef\u91cd\u590d\u8bfb\uff08mysql \u9ed8\u8ba4\uff09<\/h5>\n\n\n\n
    \u4ea7\u751f\u7684\u95ee\u9898\uff1a\u5e7b\u8bfb<\/p>\n\n\n\n
    4.serializable\uff1a\u4e32\u884c\u5316\uff08\u9501\u4f4f\u6b64\u8868\uff0c\u522b\u7684\u4e8b\u52a1\u4e0d\u53ef\u8bfb\u53d6\u548c\u64cd\u4f5c\uff09<\/h5>\n\n\n\n
    \u53ef\u4ee5\u89e3\u51b3\u6240\u6709\u7684\u95ee\u9898<\/p>\n","protected":false},"excerpt":{"rendered":"
    \u6982\u5ff5\uff1a\u4e8b\u52a1\u662f\u591a\u4e2a sql \u64cd\u4f5c\u7684\u96c6\u5408\uff0c\u8fd9\u4e9b\u64cd\u4f5c\u8981\u4e48\u540c\u65f6\u6210\u529f\uff0c\u8981\u4e48\u540c\u65f6\u5931\u8d25\u3002 1.\u4e8b\u52a1\u7684\u64cd\u4f5c 1.\u5f00\u542f\u4e8b\u52a1 \u53ea\u6709… \u7ee7\u7eed\u9605\u8bfb SQL \u4e8b\u52a1<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[4],"tags":[],"_links":{"self":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts\/104"}],"collection":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/comments?post=104"}],"version-history":[{"count":2,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts\/104\/revisions"}],"predecessor-version":[{"id":107,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/posts\/104\/revisions\/107"}],"wp:attachment":[{"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/media?parent=104"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/categories?post=104"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.52dixiaowo.com\/db\/wp-json\/wp\/v2\/tags?post=104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}