Replace character in all database fields

Question

We received an MSSQL database with many tables and fields which we need to clean. One of the things we need to do is remove all quotes (chr(34) and chr(39)) from any text fields.

Looking for a way to do this automatically instead of manually.

Answer 1

A non-set based approach:
The below sproc basically does what you need.
It uses nested WHILE loops

• the parent WHILE loop gets all user defined tables
• the nested WHILE loop goes through all char-based columns (which you can modify). Then it uses dynamic SQL to update with new string.

For many tables and large sized tables, this would obviously take quite a while to complete. I am sure this can be optimized better.
If anyone can find a set-based approach, that would be something.

Source & Courtesy: Vyaskn

CREATE PROC SearchAndReplace
(
    @SearchStr nvarchar(100),
    @ReplaceStr nvarchar(100)
)
AS
BEGIN

    SET NOCOUNT ON

    DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110), @SQL nvarchar(4000), @RCTR int
    SET  @TableName = ''
    SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
    SET @RCTR = 0

    WHILE @TableName IS NOT NULL
    BEGIN
        SET @ColumnName = ''
        SET @TableName = 
        (
            SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
            FROM    INFORMATION_SCHEMA.TABLES
            WHERE       TABLE_TYPE = 'BASE TABLE'
                AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
                AND OBJECTPROPERTY(
                        OBJECT_ID(
                            QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                             ), 'IsMSShipped'
                               ) = 0
        )

        WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
        BEGIN
            SET @ColumnName =
            (
                SELECT MIN(QUOTENAME(COLUMN_NAME))
                FROM    INFORMATION_SCHEMA.COLUMNS
                WHERE       TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                    AND TABLE_NAME  = PARSENAME(@TableName, 1)
                    AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
                    AND QUOTENAME(COLUMN_NAME) > @ColumnName
            )

            IF @ColumnName IS NOT NULL
            BEGIN
                SET @SQL=   'UPDATE ' + @TableName + 
                        ' SET ' + @ColumnName 
                        + ' =  REPLACE(' + @ColumnName + ', ' 
                        + QUOTENAME(@SearchStr, '''') + ', ' + QUOTENAME(@ReplaceStr, '''') + 
                        ') WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
                EXEC (@SQL)
                SET @RCTR = @RCTR + @@ROWCOUNT
            END
        END 
    END

    SELECT 'Replaced ' + CAST(@RCTR AS varchar) + ' occurence(s)' AS 'Outcome'
END