Doing a Search Replace Across a DB, with Wildcards

  • Hi,

    I am currently trying to find a way to search/replace certain character strings across an entire database. I found the script (below), which seems to do a good job with exact words, but doesn't seem to work well with wildcards in the string.

    For example, I want to look for:

    <title>text</title>more text

    and replace everything from <title> to the end of the string with 'nothing' '', I've tried modifying the code below with set values for @SearchStr and @Replacestr.

    I've also wanted to alter the code to just search in one table but wasn't sure how to do it here. Additionally a print of the lines (and their tables) which get replaced would be desirable.

    Am I on the right line here, or what might make this code work better to suit my needs here?

    Thanks for any helpful input or leads. 🙂

    note: I tried to contact the author of this great script, but it seems his site contact info is no longer functioning.

    Kind Regards

    USE [cop]

    GO

    /****** Object: StoredProcedure [dbo].[SearchAllTablesAndReplace_4] Script Date: 11/12/2015 2:31:31 PM ******/

    SET ANSI_NULLS ON

    GO

    SET QUOTED_IDENTIFIER ON

    GO

    CREATE PROC [dbo].[SearchAllTablesAndReplace_4]

    --(

    -- @SearchStr nvarchar(100)

    -- ,

    -- @ReplaceStr nvarchar(100)

    --)

    AS

    BEGIN

    -- Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.

    -- Purpose: To search all columns of all tables for a given search string and replace it with another string

    -- Written by: Narayana Vyas Kondreddi

    -- Site: http://vyaskn.tripod.com

    -- Tested on: SQL Server 7.0 and SQL Server 2000

    -- Date modified: 2nd November 2002 13:50 GMT

    SET NOCOUNT ON

    DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110), @SQL nvarchar(4000), @RCTR int ,@SearchStr nvarchar(110), @ReplaceStr nvarchar(110)

    SET @TableName = ''

    SET @SearchStr = '%</title>%'

    SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

    SET @ReplaceStr = ''

    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

    GO

  • To debug replace

    EXEC (@SQL)

    with

    PRINT @SQL

    You will see the SQL it generates.

    You can copy a line back into a SQL Server Management Studio query window, and run it (or see whether SSMS' parser detects a syntax error).

    Next, refer to String Functions (Transact-SQL) and Wildcards in Transact-SQL. Your rewritten SET @SQL = string expression should probably use LIKE, %, LEFT, and CHARINDEX. Remember to escape apostrophes within the @SQL string, by doubling them.

    It would be best to not[/I] use QUOTENAME the way the author is using it with @SearchStr and @ReplaceStr:crazy:. QUOTENAME returns NVARCHAR(258), because it is designed to handle schema-qualified object names (==not all strings). You can expect QUOTENAME to fail (truncate results), when its string argument is greater than 258 characters. A more robust solution is to simply use escaped apostrophes within @SQL's string, on either side of concatenations with @SearchStr and @ReplaceStr.

  • You can also use "SELECT @SQL" which will do the same thing as PRINT but just stick it in the RESULTS tab instead of the MESSAGES tab.

    Brandie Tarvin, MCITP Database AdministratorLiveJournal Blog: http://brandietarvin.livejournal.com/[/url]On LinkedIn!, Google+, and Twitter.Freelance Writer: ShadowrunLatchkeys: Nevermore, Latchkeys: The Bootleg War, and Latchkeys: Roscoes in the Night are now available on Nook and Kindle.

  • Thanks,

    I've been working on this search/replace string and had a question about why the replace still is not occurring.

    Below is the actual SQL I've been using in test:

    UPDATE [dbo].[tbl_a]

    SET [a_col] = REPLACE([a_col],'</title>%','')

    WHERE [a_col] LIKE '%</title>%'

    When used in a SELECT statement, the 'LIKE' clause, as above, does find the occurrences of the '%</title>%' string; however, no replace occurs.

    There is a message, however, stating that x number of rows was affected.

    I would like for all text, beginning with "</title>," through the end of the string, to be replaced with nothing ('').

    Are my escaped characters in need of editing?

    Thanks 🙂

  • Your escape characters need escaping. @=)

    Brandie Tarvin, MCITP Database AdministratorLiveJournal Blog: http://brandietarvin.livejournal.com/[/url]On LinkedIn!, Google+, and Twitter.Freelance Writer: ShadowrunLatchkeys: Nevermore, Latchkeys: The Bootleg War, and Latchkeys: Roscoes in the Night are now available on Nook and Kindle.

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