{"id":3114,"date":"2023-01-03T20:07:11","date_gmt":"2023-01-03T12:07:11","guid":{"rendered":"https:\/\/qaqaq.top\/?p=3114"},"modified":"2023-01-03T20:07:12","modified_gmt":"2023-01-03T12:07:12","slug":"%e5%8a%a8%e6%80%81sql","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=3114","title":{"rendered":"\u52a8\u6001SQL"},"content":{"rendered":"\n

Mybatis\u6846\u67b6\u7684\u52a8\u6001SQL\u6280\u672f\u662f\u4e00\u79cd\u6839\u636e\u7279\u5b9a\u6761\u4ef6\u52a8\u6001\u62fc\u88c5SQL\u8bed\u53e5\u7684\u529f\u80fd\uff0c\u5b83\u5b58\u5728\u7684\u610f\u4e49\u662f\u4e3a\u4e86\u89e3\u51b3
\u62fc\u63a5SQL\u8bed\u53e5\u5b57\u7b26\u4e32\u65f6\u7684\u75db\u70b9\u95ee\u9898\u3002<\/p>\n\n\n\n

1\u3001if<\/h2>\n\n\n\n

if\u6807\u7b7e\u53ef\u901a\u8fc7test\u5c5e\u6027\u7684\u8868\u8fbe\u5f0f\u8fdb\u884c\u5224\u65ad\uff0c\u82e5\u8868\u8fbe\u5f0f\u7684\u7ed3\u679c\u4e3atrue\uff0c\u5219\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9\u4f1a\u6267\u884c\uff1b\u53cd\u4e4b\u6807\u7b7e\u4e2d
\u7684\u5185\u5bb9\u4e0d\u4f1a\u6267\u884c<\/p>\n\n\n\n

    <!--List<Emp> getEmpListByMoreTJ(Emp emp);-->\r\n    <select id=\"getEmpListByMoreTJ\" resultType=\"Emp\">\r\n        select * from t_emp where 1=1\r\n        <if test=\"ename != '' and ename != null\">\r\n            and ename = #{ename}\r\n        <\/if>\r\n        <if test=\"age != '' and age != null\">\r\n            and age = #{age}\r\n        <\/if>\r\n        <if test=\"sex != '' and sex != null\">\r\n            and sex = #{sex}\r\n        <\/if>\r\n    <\/select><\/code><\/pre>\n\n\n\n
2\u3001where<\/h2>\n\n\n\n
    <select id=\"getEmpListByMoreTJ2\" resultType=\"Emp\">\r\n        select * from t_emp\r\n        <where>\r\n            <if test=\"ename != '' and ename != null\">\r\n                ename = #{ename}\r\n            <\/if>\r\n            <if test=\"age != '' and age != null\">\r\n                and age = #{age}\r\n            <\/if>\r\n            <if test=\"sex != '' and sex != null\">\r\n                and sex = #{sex}\r\n            <\/if>\r\n        <\/where>\r\n    <\/select><\/code><\/pre>\n\n\n\n
\n
where\u548cif\u4e00\u822c\u7ed3\u5408\u4f7f\u7528\uff1a<\/p>\n\n\n\n
a>\u82e5where\u6807\u7b7e\u4e2d\u7684if\u6761\u4ef6\u90fd\u4e0d\u6ee1\u8db3\uff0c\u5219where\u6807\u7b7e\u6ca1\u6709\u4efb\u4f55\u529f\u80fd\uff0c\u5373\u4e0d\u4f1a\u6dfb\u52a0where\u5173\u952e\u5b57<\/p>\n\n\n\n
b>\u82e5where\u6807\u7b7e\u4e2d\u7684if\u6761\u4ef6\u6ee1\u8db3\uff0c\u5219where\u6807\u7b7e\u4f1a\u81ea\u52a8\u6dfb\u52a0where\u5173\u952e\u5b57\uff0c\u5e76\u5c06\u6761\u4ef6\u6700\u524d\u65b9\u591a\u4f59\u7684
and\u53bb\u6389<\/p>\n\n\n\n
\u6ce8\u610f\uff1awhere\u6807\u7b7e\u4e0d\u80fd\u53bb\u6389\u6761\u4ef6\u6700\u540e\u591a\u4f59\u7684and<\/p>\n<\/blockquote>\n\n\n\n
3\u3001trim<\/h2>\n\n\n\n
    <select id=\"getEmpListByMoreTJ\" resultType=\"Emp\">\r\n        select * from t_emp\r\n        <trim prefix=\"where\" suffixOverrides=\"and\">\r\n            <if test=\"ename != '' and ename != null\">\r\n                ename = #{ename} and\r\n            <\/if>\r\n            <if test=\"age != '' and age != null\">\r\n                age = #{age} and\r\n            <\/if>\r\n            <if test=\"sex != '' and sex != null\">\r\n                sex = #{sex}\r\n            <\/if>\r\n        <\/trim>\r\n    <\/select><\/code><\/pre>\n\n\n\n
\n
trim\u7528\u4e8e\u53bb\u6389\u6216\u6dfb\u52a0\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9<\/p>\n\n\n\n
\u5e38\u7528\u5c5e\u6027\uff1a<\/p>\n\n\n\n
prefix\uff1a\u5728trim\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9\u7684\u524d\u9762\u6dfb\u52a0\u67d0\u4e9b\u5185\u5bb9<\/p>\n\n\n\n
prefixOverrides\uff1a\u5728trim\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9\u7684\u524d\u9762\u53bb\u6389\u67d0\u4e9b\u5185\u5bb9<\/p>\n\n\n\n
suffix\uff1a\u5728trim\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9\u7684\u540e\u9762\u6dfb\u52a0\u67d0\u4e9b\u5185\u5bb9<\/p>\n\n\n\n
suffixOverrides\uff1a\u5728trim\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9\u7684\u540e\u9762\u53bb\u6389\u67d0\u4e9b\u5185\u5bb9<\/p>\n<\/blockquote>\n\n\n\n
4\u3001choose\u3001when\u3001otherwise<\/h2>\n\n\n\n
choose \u3001 when \u3001 otherwise\u76f8\u5f53\u4e8eif\u2026else if..else<\/p>\n\n\n\n
    <!--List<Emp> getEmpListByChoose(Emp emp);-->\r\n    <select id=\"getEmpListByChoose\" resultType=\"Emp\">\r\n        select <include refid=\"empColumns\"><\/include> from t_emp\r\n        <where>\r\n            <choose>\r\n                <when test=\"ename != '' and ename != null\">\r\n                    ename = #{ename}\r\n                <\/when>\r\n                <when test=\"age != '' and age != null\">\r\n                    age = #{age}\r\n                <\/when>\r\n                <when test=\"sex != '' and sex != null\">\r\n                    sex = #{sex}\r\n                <\/when>\r\n                <when test=\"email != '' and email != null\">\r\n                    email = #{email}\r\n                <\/when>\r\n            <\/choose>\r\n        <\/where>\r\n    <\/select><\/code><\/pre>\n\n\n\n
5\u3001foreach<\/h2>\n\n\n\n
    <!--int insertMoreEmp(List<Emp> emps);-->\r\n    <insert id=\"insertMoreEmp\">\r\n        insert into t_emp values\r\n        <foreach collection=\"emps\" item=\"emp\" separator=\",\">\r\n            (null,#{emp.ename},#{emp.age},#{emp.sex},#{emp.email},null)\r\n        <\/foreach>\r\n    <\/insert>\r\n    <!--int deleteMoreByArray(int[] eids);-->\r\n    <delete id=\"deleteMoreByArray\">\r\n        delete from t_emp where\r\n        <foreach collection=\"eids\" item=\"eid\" separator=\"or\">\r\n            eid = #{eid}\r\n        <\/foreach>\r\n    <\/delete>\r\n    <!--int deleteMoreByArray(int[] eids);-->\r\n    <delete id=\"deleteMoreByArray\">\r\n        delete from t_emp where eid in\r\n        <foreach collection=\"eids\" item=\"eid\" separator=\",\" open=\"(\" close=\")\">\r\n            #{eid}\r\n        <\/foreach>\r\n    <\/delete><\/code><\/pre>\n\n\n\n
\n
\u5c5e\u6027\uff1a<\/p>\n\n\n\n
collection\uff1a\u8bbe\u7f6e\u8981\u5faa\u73af\u7684\u6570\u7ec4\u6216\u96c6\u5408<\/p>\n\n\n\n
item\uff1a\u8868\u793a\u96c6\u5408\u6216\u6570\u7ec4\u4e2d\u7684\u6bcf\u4e00\u4e2a\u6570\u636e<\/p>\n\n\n\n
separator\uff1a\u8bbe\u7f6e\u5faa\u73af\u4f53\u4e4b\u95f4\u7684\u5206\u9694\u7b26<\/p>\n\n\n\n
open\uff1a\u8bbe\u7f6eforeach\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9\u7684\u5f00\u59cb\u7b26<\/p>\n\n\n\n
close\uff1a\u8bbe\u7f6eforeach\u6807\u7b7e\u4e2d\u7684\u5185\u5bb9\u7684\u7ed3\u675f\u7b26<\/p>\n<\/blockquote>\n\n\n\n
6\u3001SQL\u7247\u6bb5<\/h2>\n\n\n\n
sql\u7247\u6bb5\uff0c\u53ef\u4ee5\u8bb0\u5f55\u4e00\u6bb5\u516c\u5171sql\u7247\u6bb5\uff0c\u5728\u4f7f\u7528\u7684\u5730\u65b9\u901a\u8fc7include\u6807\u7b7e\u8fdb\u884c\u5f15\u5165<\/p>\n\n\n\n
    <sql id=\"empColumns\">\n        eid,ename,age,sex,did\n    <\/sql>\n    select <include refid=\"empColumns\"><\/include> from t_emp<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
Mybatis\u6846\u67b6\u7684\u52a8\u6001SQL\u6280\u672f\u662f\u4e00\u79cd\u6839\u636e\u7279\u5b9a\u6761\u4ef6\u52a8\u6001\u62fc\u88c5SQL\u8bed\u53e5\u7684\u529f\u80fd\uff0c\u5b83\u5b58\u5728\u7684\u610f\u4e49\u662f\u4e3a\u4e86\u89e3\u51b3\u62fc\u63a5SQL […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[108],"tags":[111],"class_list":["post-3114","post","type-post","status-publish","format-standard","hentry","category-mybatis-code","tag-mybatis"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/3114"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3114"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/3114\/revisions"}],"predecessor-version":[{"id":3115,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/3114\/revisions\/3115"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3114"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3114"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3114"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}