或者像@mjwills建议的那样，你可以在没有if条件的情况下完成：
写一个WHILE循环,用来动态拼接部分SQL(关联条件部分)。 代码语言:javascript 复制 CREATEORREPLACEPROCEDURETESTAS--待拼接的字段STRVARCHAR2(128);--逗号数量,用于循环SIGNSINT;--逗号数量最大值,用于判断是否加ANDSI_MAXINT;--当前循环取到的值CURRENT_VALUEVARCHAR2(32);--存放计算值,用于判断是每组字段的前后者...
The following example has a Boolean expression (1 = 2) that is false, and therefore prints the second statement.SQL Kopiuj IF 1 = 2 PRINT 'Boolean expression is true.' ELSE PRINT 'Boolean expression is false.'; GO B. Use a query as part of a Boolean expressionThe following example ...
v_brand为NULL + OR返回true（查询返回column 1等于someValue的所有行--与brandColumn无关）
In the later part of the tutorial, we discussed creating a MySQL Function using IF-ELSE conditional construct which could then be used as part of the MySQL query and can act on the supplied input value. The IF() function and IF-ELSE is a powerful construct and is extremely useful for q...
无需加ANDIF SIGNS=SI_MAXTHEN--拼接关联条件字符串CONDITIONS :=CONDITIONS||F_ALI||TEMP.ID||'.'||CURRENT_VALUE;--拼接查询字符串QUERY_ITEMS :=QUERY_ITEMS||CURRENT_VALUE;ELSE--拼接关联条件字符串CONDITIONS :=CONDITIONS||'AND '||F_ALI||TEMP.ID||'.'||CURRENT_VALUE;--拼接查询字符串QUERY_...
SQL IF 1 = 2 PRINT 'Boolean expression is true.' ELSE PRINT 'Boolean expression is false.'; GO B. Use a query as part of a Boolean expression The following example executes a query as part of the Boolean expression. Because there are 10 bikes in theProducttable that meet the condition...
案例:使用CASE WHEN语句执行分支操作,SQL语句如下: 命令语句:select CASE WHEN 1>2 THEN 'true' ELSE 'false' END; 执行结果:六、 系统信息函数 MySQL中系统信息有数据库的版本号、当前用户名和连接数、系统字符集、最后一个自动生成的ID值等。 1. 获取mysql版本号、连接数和数据库名的函数...
<!--进行模糊查询需求1:查询男性用户,如果输入了姓名,进行模糊查找。一->select * from t_ user where sex ='男‘<iftest="name !=null and name !=''"><!-- test可以写表达示-->and user_ name like #{name}</if> 1. 2. 3. 4. 5. 6. 7. 8. 9. 测试类: @Test public...
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '.186.7)) Subject Views Written By Posted If exist Update else insert query