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    TableColumnMaxLenWHERE   TableName = @tableName;