标签:TableColumnMaxLen TableName tableName sqlserver columnName 字段 表中 WHERE DECLARE
转载来源:https://www.cnblogs.com/lizhanglong/p/6696722.html
DECLARE @tableName NVARCHAR(50)= 'home'; IF OBJECT_ID(N'TableColumnMaxLen', N'U') IS NULL BEGIN CREATE TABLE TableColumnMaxLen ( TableName NVARCHAR(50) NOT NULL , ColumnName NVARCHAR(50) NOT NULL , ColumnMaxLen INT NOT NULL , PRIMARY KEY ( TableName, ColumnName ) ); END; DECLARE @columnName NVARCHAR(50); DECLARE @columnMaxLen INT; DECLARE @sql NVARCHAR(MAX); DECLARE @initState INT= -1; DECLARE @searchingState INT= -2; IF NOT EXISTS ( SELECT 1 FROM dbo.TableColumnMaxLen WHERE TableName = @tableName ) BEGIN INSERT TableColumnMaxLen SELECT @tableName , COLUMN_NAME , @initState FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = @tableName; END; WHILE 1 = 1 BEGIN SET @columnName = ( SELECT TOP 1 ColumnName FROM TableColumnMaxLen WHERE TableName = @tableName AND ColumnMaxLen = @initState ); IF @columnName IS NULL BREAK; UPDATE TableColumnMaxLen SET ColumnMaxLen = @searchingState WHERE TableName = @tableName AND ColumnName = @columnName; SET @sql = 'SELECT @columnMaxLen=ISNULL(MAX(LEN([' + @columnName + '])), 0) FROM ' + @tableName; -- PRINT @sql; EXEC sp_executesql @sql, N'@columnMaxLen int out', @columnMaxLen OUT; UPDATE TableColumnMaxLen SET ColumnMaxLen = @columnMaxLen WHERE TableName = @tableName AND ColumnName = @columnName; END; SELECT * FROM TableColumnMaxLen WHERE TableName = @tableName;
将上面home 替换为你要查的表名称
查询效果
标签:TableColumnMaxLen,TableName,tableName,sqlserver,columnName,字段,表中,WHERE,DECLARE 来源: https://www.cnblogs.com/hao-1234-1234/p/12121215.html
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