COALESCE() --函数返回众多表达式中第一个非NULL 表达式的值 COL_LENGTH(<'table_name'>, <'column_name'>) --函数返回表中指定字段的长度值 COL_NAME( , <column_id>) --函数返回表中指定字段的名称即列名 DATALENGTH() --函数返回数据表达式的数据的实际长度 DB_ID(['database_name']) --函数返回数...
Using ISNULL() or COALESCE() is even worse (worse because the QO is able to make some assumptions if the underlying field is not nullable). Dynamic SQL side-steps this because you're able to only specify the criteria needed, leaving the QO a clean path to determine the best plan....
Checking if xp_cmdshell is enabled or not Chinese characters issue with T-SQL. Clear tempDB data CLR semaphore Clustered index update in execution plan Coalesce in JOIN condition Coalesce with Sum Code to check IBAN numbers? Collapse and Expand node in SQL editor not displaying Collate Database_...
case when IsEnable=1 then '启用' else '停用' from tb_User OQL是SOD框架的ORM查询语言，它类似L...
A key trick that is involved with this query is the following two comparisons: date1 >= coalesce(date2, date1) date12 >= coalesce(date3, date12) These two comparisons above are logically equivalent to these two comparisons: date1 >= date2 or date1 is not null and d...
whereas COALESCE is not. So the expressions ISNULL(NULL, 1) and COALESCE(NULL, 1), although equivalent, have different NULLability values. This makes a difference if you are using these expressions in computed columns and creating key constraints or making the return value of a scalar UDF dete...
问TSQL内部回报率(IRR)来自行而不是列EN–1. IDENTIY 列不能为空，不能设默认值，创建后不能使用...
CASE WHEN last_name IS NULL THEN '' ELSE ' '+last_name END Solution 2: When using the comparison operator ==, it is not possible to compare with NULL. CASE WHEN last_name is NULL THEN ... ELSE .. END instead or COALESCE:
返回第一个非空表达式 DECODE COALESCE 当前序列值 CURRVAL N/A 下一个序列值 NEXTVAL N/A 如果exp1 = exp2, 返回null DECODE NULLIF 用户登录账号ID数字 UID SUSER_ID 用户登录名 USER SUSER_NAME 用户数据库ID数字 UID USER_ID 用户数据库名 USER USER_NAME ...
WHEN @ProductNumber IS NULL THEN '%' ELSE ('%' + @ProductNumber + '%') END ProductSearch7 (@ProductNumber IS NULL OR ProductNumber LIKE @ProductNumber) should be (@ProductNumber IS NULL OR ProductNumber LIKE ('%' + @ProductNumber + '%') ...