where条件这些都是可以正常使用的 where (case when 第二字段 is not null then 第二字段 else 第一字段 end) = 值 或者where ISNULL(第二字段,第一字段) = 值 就这么正常使用就可以了 (case when 第二字段 is not null then 第二字段 else 第一字段 end)==>isnull(第二字段, 第一字段)"放在where 条件后面 第二个字...
CASE WHEN [tempdb].[dbo].[table].[a] IS NOT NULL THEN [tempdb].[dbo].[table].[a] ELSE CASE WHEN [tempdb].[dbo].[table].[b] IS NOT NULL THEN [tempdb].[dbo].[table].[b] ELSE CASE WHEN [tempdb].[dbo].[table].[c] IS NOT NULL THEN [tempdb].[dbo].[table].[c] ELSE ...
expression2 )为CASE WHEN expression1 IS NOT NULL THEN expression1 ELSE expression2 END。在...
AND CASE WHEN OBJECT_TYPE IS NOT NULL THEN 1 END = 1; 1. 2. 3. 3) 创建一个函数索引。也就是说OBJECT_TYPE IS NOT NULL的记录在索引中存储为1。如下: CREATE INDEX IDX_TEST11_MAX ON TEST11(OWNER,CASE WHEN OBJECT_TYPE IS NOT NULL THEN 1 END,CREATED) PARALLEL 4 NOLOGGING; ALTER INDE...
CREATETABLETestTable(IDINTPRIMARYKEY,NameVARCHAR(50));INSERTINTOTestTable(ID,Name)SELECTTOP1000000ROW_NUMBER()OVER(ORDERBY(SELECTNULL)),CASEWHENROW_NUMBER()OVER(ORDERBY(SELECTNULL))%2=0THENNULLELSE'Name'ENDFROMsys.columnsa,sys.columnsb; ...
CREATE INDEX idx_employees_salary_not_null ON employees(CASE WHEN salary IS NOT NULL THEN 1 END); 使用视图:您可以创建一个视图,该视图仅包含不为 NULL 的行。例如,如果您要查询名为 "employees" 的表中的 "salary" 列,您可以创建以下视图: ...
sql语句判空赋值 case when is not nul S.ELE.CT CASE WHEN column_name IS NOT NULL THEN column_name ELSE 0 END AS column_name FROM table_name; 在 MSSQL中使用CASE WHEN THEN 判断某字段是否为NULL, 和判断是否为字符或数字时的写法不一样 正确方法: CASE WHEN columnName IS NULL THEN 0 ELSE ...
如果异常类型是TApplicationException，并且异常原因是missing_result，那么可以返回null。否则，应该继续向上...
not be prefixed if the tag’s resulting body content is empty. The open value is prefixed before the prepend attribute’s value is prefixed. For example, if prepend="OR " and open="(", then the resulting combined prefix would be "OR (". ...
What is a NULL Value? A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field. Then, the field will be saved with a NULL value. ...