1、复制表(包括表结构、表数据)
SqlServer:
Select * into user_copy from user
MySql:
CREATE TABLE user_copy LIKE user;
INSERT INTO user_copy SELECT * FROM user;
2、多表连接做update
SqlServer:
UPDATE s1 SET s1.salary= s2.salary
FROM (SELECT * FROM s WHERE age>10) AS s1 JOIN s2 ON s1.uname= s2.uname
WHERE s1.uname = 'xx'
MySql:(无法直接对目标表的查询数据直接做更新,只能针对目标表操作)
UPDATE s1 JOIN s2 ON s1.uname= s2.uname
SET s1.salary= s2.salary
WHERE s1.uname = 'xx'
3、修改表字段结构
SqlServer:
ALTER TABLE user ALTER COLUMN uid INT NOT NULL
GO
ALTER TABLE user ALTER COLUMN name nvarchar(100) NOT NULL
GO
MySql:(无法直接对目标表的查询数据直接做更新,只能针对目标表操作)
ALTER TABLE user MODIFY uid INT NOT NULL COMMENT 'xx';
ALTER TABLE user MODIFY name varchar(100) NOT NULL COMMENT 'xxy';
4、添加、修改主键
SqlServer:
ALTER TABLE user ADD CONSTRAINT PK_uid_name PRIMARY KEY(uid, name)
MySql:(无法直接对目标表的查询数据直接做更新,只能针对目标表操作)
ALTER TABLE user DROP PRIMARY KEY;
ALTER TABLE user ADD PRIMARY KEY (uid, name);
5、查询数据拼接Sql语句
SqlServer:
SELECT 'insert into dbo.TableName([ID],[Name]) values ('+ CAST([ID] AS VARCHAR) + ',''' + CAST([Name] AS VARCHAR) + ''')'
FROM dbo.TableName WHERE ID > 433
6、查询字段首位为汉字
SqlServer:
SELECT * FROM 表名 WHERE ascii(字段)>127
7、查询字段包含汉字(任意位)
SqlServer:
SELECT * FROM 表名 WHERE 字段 LIKE '%[吖-座]%' --[吖-座]是中文字符集第一个到最后一个的范围
8、SqlServer和Mysql插入记录前判断是否存在,存在则插入,不存在则修改
SqlServer:
if NOT exists(SELECT * FROM Setting WHERE ID=0) INSERT INTO Setting(ID,Title,SearchKeys, ServiceIntervalSecond,SleepMillisecondPerSearch) VALUES(0,@title,@searchKeys,@serviceIntervalSecond,@sleepMillisecondPerSearch) ELSE UPDATE Setting SET Title=@title,SearchKeys=@searchKeys,ServiceIntervalSecond=@serviceIntervalSecond, SleepMillisecondPerSearch=@sleepMillisecondPerSearch
MySqL:
INSERT INTO `his_examine_result` (Mid,His_Examine_Mid, His_File_Mid, ResultType, His_Employee_Mid, His_Employee_Name, ExamineResult, ExamineItemName, ExamineStandardName, ExamineItemUnit, ExamineHighValue, ExamineLowValue, ExamineDiscription, Discription) VALUES ($mid,$examineMid,$fileMid,1,null,null,'',$itemName,$standName,$itemUnit,$highValue,$lowValue,'','') ON DUPLICATE KEY UPDATE ExamineResult=$result,ExamineDiscription=$dis
9、创建索引
SqlServer:
IF NOT EXISTS(SELECT * FROM sysindexes WHERE id = OBJECT_ID('T_Person_info') and name = 'idx_pCode')
CREATE NONCLUSTERED INDEX idx_pCode ON [dbo].T_Person_info
(
pCode ASC
) ON [PRIMARY];