181

How can I drop all tables whose names begin with a given string?

I think this can be done with some dynamic SQL and the INFORMATION_SCHEMA tables.

0

18 Answers 18

181

You may need to modify the query to include the owner if there's more than one in the database.

DECLARE @cmd varchar(4000)
DECLARE cmds CURSOR FOR
SELECT 'drop table [' + Table_Name + ']'
FROM INFORMATION_SCHEMA.TABLES
WHERE Table_Name LIKE 'prefix%'

OPEN cmds
WHILE 1 = 1
BEGIN
    FETCH cmds INTO @cmd
    IF @@fetch_status != 0 BREAK
    EXEC(@cmd)
END
CLOSE cmds;
DEALLOCATE cmds

This is cleaner than using a two-step approach of generate script plus run. But one advantage of the script generation is that it gives you the chance to review the entirety of what's going to be run before it's actually run.

I know that if I were going to do this against a production database, I'd be as careful as possible.

Edit Code sample fixed.

4
  • 6
    You may have to run this script several times because of foreign key constraints between master and detail tables. Dec 26, 2008 at 5:24
  • 8
    In SQL Server 2005 I had to change the last two lines to close cmds; deallocate cmds. Apr 26, 2011 at 14:08
  • 1
    Warning: This solution may also delete tables created by SQL Server! My solution below avoids this and deletes tables in foreign key dependency order. Jul 19, 2015 at 1:15
  • 1
    This did not work for me. The answer to this question worked: stackoverflow.com/questions/5116296/…
    – Ayushmati
    May 11, 2020 at 19:18
142
SELECT 'DROP TABLE "' + TABLE_NAME + '"' 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_NAME LIKE '[prefix]%'

This will generate a script.

Adding clause to check existence of table before deleting:

SELECT 'IF OBJECT_ID(''' +TABLE_NAME + ''') IS NOT NULL BEGIN DROP TABLE [' + TABLE_NAME + '] END;' 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_NAME LIKE '[prefix]%'
8
  • 15
    I might add to remove the brackets when replacing "prefix" with your target prefix.
    – Levitikon
    May 20, 2012 at 15:31
  • 16
    MYSQL: SELECT concat('DROP TABLE ',TABLE_NAME,";") as data FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME LIKE '[prefix]%' --- for those who like me found this thread
    – Andre
    Nov 6, 2012 at 0:27
  • 1
    The result contains also views
    – Ondra
    Mar 29, 2013 at 13:01
  • 3
    Don't forget to escape _ if that's part of your prefix, eg. WHERE TABLE_NAME LIKE 'em\_%' ESCAPE '\';
    – EM0
    Sep 29, 2015 at 14:37
  • 8
    This generates a script, but how does one execute the script?
    – daOnlyBG
    Aug 4, 2017 at 20:45
19

This will get you the tables in foreign key order and avoid dropping some of the tables created by SQL Server. The t.Ordinal value will slice the tables into dependency layers.

WITH TablesCTE(SchemaName, TableName, TableID, Ordinal) AS
(
    SELECT OBJECT_SCHEMA_NAME(so.object_id) AS SchemaName,
        OBJECT_NAME(so.object_id) AS TableName,
        so.object_id AS TableID,
        0 AS Ordinal
    FROM sys.objects AS so
    WHERE so.type = 'U'
        AND so.is_ms_Shipped = 0
        AND OBJECT_NAME(so.object_id)
        LIKE 'MyPrefix%'

    UNION ALL
    SELECT OBJECT_SCHEMA_NAME(so.object_id) AS SchemaName,
        OBJECT_NAME(so.object_id) AS TableName,
        so.object_id AS TableID,
        tt.Ordinal + 1 AS Ordinal
    FROM sys.objects AS so
        INNER JOIN sys.foreign_keys AS f
            ON f.parent_object_id = so.object_id
                AND f.parent_object_id != f.referenced_object_id
        INNER JOIN TablesCTE AS tt
            ON f.referenced_object_id = tt.TableID
    WHERE so.type = 'U'
        AND so.is_ms_Shipped = 0
        AND OBJECT_NAME(so.object_id)
        LIKE 'MyPrefix%'
)
SELECT DISTINCT t.Ordinal, t.SchemaName, t.TableName, t.TableID
FROM TablesCTE AS t
    INNER JOIN
    (
        SELECT
            itt.SchemaName AS SchemaName,
            itt.TableName AS TableName,
            itt.TableID AS TableID,
            Max(itt.Ordinal) AS Ordinal
        FROM TablesCTE AS itt
        GROUP BY itt.SchemaName, itt.TableName, itt.TableID
    ) AS tt
        ON t.TableID = tt.TableID
            AND t.Ordinal = tt.Ordinal
ORDER BY t.Ordinal DESC, t.TableName ASC
2
10

On Oracle XE this works:

SELECT 'DROP TABLE "' || TABLE_NAME || '";'
FROM USER_TABLES
WHERE TABLE_NAME LIKE 'YOURTABLEPREFIX%'

Or if you want to remove the constraints and free up space as well, use this:

SELECT 'DROP TABLE "' || TABLE_NAME || '" cascade constraints PURGE;'
FROM USER_TABLES
WHERE TABLE_NAME LIKE 'YOURTABLEPREFIX%'

Which will generate a bunch of DROP TABLE cascade constraints PURGE statements...

For VIEWS use this:

SELECT 'DROP VIEW "' || VIEW_NAME || '";'
FROM USER_VIEWS
WHERE VIEW_NAME LIKE 'YOURVIEWPREFIX%'
1
  • 1
    Worked perfectly. Had 61,037 empty tables to delete from a db used for QA. I used the cascade constraints example. Generated the output then copied it all into a script and ran it. Took forever but it worked like a charm! Thanks! Oct 30, 2019 at 16:52
9
EXEC sp_MSforeachtable 'if PARSENAME("?",1) like ''%CertainString%'' DROP TABLE ?'

Edit:

sp_MSforeachtable is undocumented hence not suitable for production because it's behavior may vary depending on MS_SQL version.

1
  • Awesome one-liner! This should be voted to the top. Dec 20, 2017 at 17:17
8

Here is my solution:

SELECT CONCAT('DROP TABLE `', TABLE_NAME,'`;') 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_NAME LIKE 'TABLE_PREFIX_GOES_HERE%';

And of course you need to replace TABLE_PREFIX_GOES_HERE with your prefix.

7

I saw this post when I was looking for mysql statement to drop all WordPress tables based on @Xenph Yan here is what I did eventually:

SELECT CONCAT(  'DROP TABLE `', TABLE_NAME,  '`;' ) AS query
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_NAME LIKE  'wp_%'

this will give you the set of drop queries for all tables begins with wp_

5
CREATE PROCEDURE usp_GenerateDROP
    @Pattern AS varchar(255)
    ,@PrintQuery AS bit
    ,@ExecQuery AS bit
AS
BEGIN
    DECLARE @sql AS varchar(max)

    SELECT @sql = COALESCE(@sql, '') + 'DROP TABLE [' + TABLE_NAME + ']' + CHAR(13) + CHAR(10)
    FROM INFORMATION_SCHEMA.TABLES
    WHERE TABLE_NAME LIKE @Pattern

    IF @PrintQuery = 1 PRINT @sql
    IF @ExecQuery = 1 EXEC (@sql)
END
3

Xenph Yan's answer was far cleaner than mine but here is mine all the same.

DECLARE @startStr AS Varchar (20)
SET @startStr = 'tableName'

DECLARE @startStrLen AS int
SELECT @startStrLen = LEN(@startStr)

SELECT 'DROP TABLE ' + name FROM sysobjects
WHERE type = 'U' AND LEFT(name, @startStrLen) = @startStr

Just change tableName to the characters that you want to search with.

3

This worked for me.

DECLARE @sql NVARCHAR(MAX) = N'';

SELECT @sql += '
DROP TABLE ' 
    + QUOTENAME(s.name)
    + '.' + QUOTENAME(t.name) + ';'
    FROM sys.tables AS t
    INNER JOIN sys.schemas AS s
    ON t.[schema_id] = s.[schema_id] 
    WHERE t.name LIKE 'something%';

PRINT @sql;
-- EXEC sp_executesql @sql;
1
select 'DROP TABLE ' + name from sysobjects
where type = 'U' and sysobjects.name like '%test%'

-- Test is the table name

1
  • this doesn't actually execute anything, just return a bunch of commands. Mar 12, 2014 at 16:57
1
SELECT 'if object_id(''' + TABLE_NAME + ''') is not null begin drop table "' + TABLE_NAME + '" end;' 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_NAME LIKE '[prefix]%'
1

I had to do a slight derivation on Xenph Yan's answer I suspect because I had tables not in the default schema.

SELECT 'DROP TABLE Databasename.schema.' + TABLE_NAME 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_NAME LIKE 'strmatch%'
1

In case of temporary tables, you might want to try

SELECT 'DROP TABLE "' + t.name + '"' 
FROM tempdb.sys.tables t
WHERE t.name LIKE '[prefix]%'
1

I would like to post my proposal of the solution which DROP (not just generate and select a drop commands) all tables based on the wildcard (e.g. "table_20210114") older than particular amount of days.

DECLARE 
    @drop_command NVARCHAR(MAX) = '',
    @system_time date,
    @table_date nvarchar(8),
    @older_than int = 7
    
Set @system_time = (select getdate() - @older_than)
Set @table_date = (SELECT CONVERT(char(8), @system_time, 112))

SELECT @drop_command += N'DROP TABLE ' + QUOTENAME(SCHEMA_NAME(schema_id)) + '.' + QUOTENAME([Name]) + ';'
FROM <your_database_name>.sys.tables
WHERE [Name] LIKE 'table_%' AND RIGHT([Name],8) < @table_date

SELECT @drop_command
 
EXEC sp_executesql @drop_command
1

If your query returns more than one line, you can collect the results and merge them into a query.

declare @Tables as nvarchar(max) = '[schemaName].['
select @Tables =@Tables + TABLE_NAME +'],[schemaName].['
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_TYPE='BASE TABLE'
AND TABLE_SCHEMA = 'schemaName'
AND TABLE_NAME like '%whateverYourQueryIs%'

select @Tables =  Left(@Tables,LEN(@Tables)-13) --trying to remove last ",[schemaName].[" part, so you need to change this 13 with actual lenght 

--print @Tables

declare @Query as nvarchar(max) = 'Drop table ' +@Tables 

--print @Query


exec sp_executeSQL @Query
0

Try following code:

declare @TableLst table(TblNames nvarchar(500))
insert into @TableLst (TblNames)
SELECT 'DROP TABLE [' + Table_Name + ']'
FROM INFORMATION_SCHEMA.TABLES
WHERE Table_Name LIKE 'yourFilter%'
WHILE ((select COUNT(*) as CntTables from @TableLst) > 0)
BEGIN
    declare @ForExecCms nvarchar(500) = (select top(1) TblNames from @TableLst)
    EXEC(@ForExecCms)
    delete from @TableLst where TblNames = @ForExecCms
END

This SQL script is executed without using a cursor.

0

If you suddenly need to delete tables linked by foreign keys.

USE [CentralIntake]
GO

DECLARE @name VARCHAR(200);
DECLARE @DropForeignKeyProcedure varchar(4000); 
DECLARE @DropTableProcedure varchar(4000); 

/*TEST*/ SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE Table_Name LIKE '%_unused'

DECLARE tb_cursor CURSOR FOR 
SELECT TABLE_NAME 
FROM INFORMATION_SCHEMA.TABLES WHERE Table_Name LIKE '%_unused';

OPEN tb_cursor  
FETCH NEXT FROM tb_cursor INTO @name 

WHILE @@FETCH_STATUS = 0  
BEGIN  

/*TEST*/ SELECT 'ALTER TABLE [' +  OBJECT_SCHEMA_NAME(parent_object_id) + '].[' + OBJECT_NAME(parent_object_id) + '] DROP CONSTRAINT [' + name + ']'    FROM sys.foreign_keys WHERE referenced_object_id = object_id(@name)

    DECLARE fk_cursor CURSOR FOR
    (SELECT 'ALTER TABLE [' +  OBJECT_SCHEMA_NAME(parent_object_id) + '].[' + OBJECT_NAME(parent_object_id) + '] DROP CONSTRAINT [' + name + ']'
    FROM sys.foreign_keys
    WHERE referenced_object_id = object_id(@name));

    OPEN fk_cursor
    FETCH NEXT FROM fk_cursor INTO @DropForeignKeyProcedure
    WHILE @@FETCH_STATUS = 0  
        BEGIN   
            EXEC (@DropForeignKeyProcedure);
            FETCH NEXT FROM fk_cursor INTO @DropForeignKeyProcedure
        END
    CLOSE fk_cursor  
    DEALLOCATE fk_cursor

    SET @DropTableProcedure = (SELECT 'DROP TABLE [' +  TABLE_CATALOG  + '].[' + TABLE_SCHEMA + '].[' + @name + ']'
    FROM INFORMATION_SCHEMA.TABLES
    where TABLE_NAME = @name)

    EXEC(@DropTableProcedure)

    FETCH NEXT FROM tb_cursor INTO @name 
END 

CLOSE tb_cursor  
DEALLOCATE tb_cursor

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