游标(Transact-SQL) 数据定义语言 (DDL) 语句 (Transact-SQL) 数据操作语言 (DML) 语句 (Transact-SQL) 数据类型 (Transact-SQL) EXECUTE 表达式(Transact-SQL) 语言元素 (Transact-SQL) 管理命令 运算符 (Transact-SQL) 谓词(Transact-SQL) PRINT (Transact-SQ
SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) Specifies ISO compliant behavior of the Equals (=) and Not Equal To (<>) comparison operators when they are used withNULLvalues in SQL Server. ...
The database options described in the following sections are values that you can set for sessions that don't explicitly provide other set option values. Syntax syntaxsql Copy ALTER DATABASE { database_name | CURRENT } SET { [ ,...n ] [ WITH <termination> ] } ::= { <accelerated_...
很明显该SQL存在大量拼接重复语句的问题,在一个大循环中重复调用造成性能消耗。而且随着List的增大,生成的SQL语句也会非常冗长。 优化方式:将原SQL改为in条件查询,减少查询次数。 修改后的SQL为: SELECT*** FROM ssa JOIN ssi ON###AND###AND###WHEREssa.xxxIN(<foreachcollection="list"item="item"index=...
CREATE TABLE `test` (`ID` int(11) NOT NULL,`LIST` varchar(255) DEFAULT NULL,PRIMARY KEY (`ID`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;-- --- Records of test-- ---INSERT INTO `test` VALUES ('1', 'AA,BB,CC');INSERT INTO `test` VALUES ('2', 'AA,BB');INSERT INTO `test` V...
SQL 複製 PRINT '*** Setting ANSI_WARNINGS ON'; GO SET ANSI_WARNINGS ON; GO PRINT 'Testing NULL in aggregate'; GO SELECT a, SUM(b) FROM T1 GROUP BY a; GO PRINT 'Testing String Overflow in INSERT'; GO INSERT INTO T1 VALUES (3, 3, 'Text string longer than 20 characters'); GO...
3381ssl yttSQL>create tablet1(id int primary key,r1 int);QueryOK,0rowsaffected(0.1561sec)MySQL localhost:3381ssl yttSQL>insert t1values(1,100);QueryOK,1rowaffected(0.0185sec)MySQL localhost:3381ssl yttSQL>table t1;+---+---+|id|r1|+---+---+|1|100|+---+---+1rowinset(0.0004sec...
SQL> set define off SQL> insert into customers (customer_name) values ('Marks & Spencers Ltd'); 1 row created. SQL> select customer_name from customers; CUSTOMER_NAME --- Marks & Spencers Ltd 上面的例子你需要customers表,但是有一个表是所有Oracle数据库都拥有的,没错就是dual。如果想了解dua...
Array data type in SQL server Array's IN SQL SERVER? ASCII values for extended characters Assign empty string '' if datetime is null Assign EXEC output to Variable Assigning NULL value to column name using Case Statement of where is SQL SERVER 2008 atomic if not exists() and insert or upd...
INSERT INTO dbo.Test VALUES (1, "'Text in single quotes'") INSERT INTO dbo.Test VALUES (2, '''Text in single quotes''') INSERT INTO dbo.Test VALUES (3, 'Text with 2 ''' single quotes') INSERT INTO dbo.Test VALUES (4, '"Text in double quotes"') INSERT INTO dbo.Test VALUES...