Question

DECLARE @COLNAME VARCHAR(100)
DECLARE @CREATE VARCHAR (1000)
DECLARE @TYPE VARCHAR(1)
SET @COLNAME = ''
SET @TYPE = 5
SET @CREATE = 'CRATE TABLE TABLE_TYPE_' + @TYPE + '('


DECLARE MyCursor CURSOR FOR
SELECT Name FROM LAYOUT WHERE RecordType = @TYPE
ORDER BY Start

OPEN MyCursor
FETCH NEXT FROM MyCursor INTO @COLNAME


    WHILE @@FETCH_STATUS = 0
    BEGIN
    SET @COLNAME = REPLACE(@COLNAME, 'WX-', '')
    SET @COLNAME = REPLACE(@COLNAME, '(', '')
    SET @COLNAME = REPLACE(@COLNAME, ')', '')
    SET @CREATE = @CREATE + '[' + @COLNAME + ']' + ' VARCHAR(1000),'
    FETCH NEXT FROM MyCursor INTO @COLNAME
    END


    CLOSE MyCursor
    DEALLOCATE MyCursor
    SET @CREATE = LEFT(@CREATE, len(@CREATE) -1) + ')' --get rid of last comma
    PRINT (@CREATE)   --EXEC (@CREATE)

似乎MS的最大限制。当我打印@CREATE时，许多行已被切断。 EX。有300列但不知何故它只能打印出200列如何在不中断的情况下生成create table语句。

我知道有些人会建议不要使用光标，但由于一个表的列数太多，因此输入所有列名称将非常耗时。

Answer 1

你真的不应该使用光标。不仅可以不使用光标，它更简单：

DECLARE @CREATE VARCHAR (max),
        @TYPE int = 5

SET @CREATE = 'CRATE TABLE TABLE_TYPE_' + CAST(@TYPE as varchar) + '('

SELECT @CREATE = @CREATE + REPLACE(
            REPLACE(
              REPLACE([Name], 'WX-', ''),
            '(', ''),
        ')', '') + ' VARCHAR(1000),'
FROM Layout
WHERE RecordType = @TYPE

SET @CREATE = LEFT(@CREATE, len(@CREATE) -1) + ')' --get rid of last comma

PRINT @CREATE

see fiddle here

无法执行游标

1 个答案: