How to drop all tables from a database with one SQL query? - sql

Question

I don't want to type all tables' name to drop all of them. Is it possible with one query?

Answer 1

Use the INFORMATION_SCHEMA.TABLES view to get the list of tables. Generate Drop scripts in the select statement and drop it using Dynamic SQL:
DECLARE #sql NVARCHAR(max)=''
SELECT #sql += ' Drop table ' + QUOTENAME(TABLE_SCHEMA) + '.'+ QUOTENAME(TABLE_NAME) + '; '
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
Exec Sp_executesql #sql
Sys.Tables Version
DECLARE #sql NVARCHAR(max)=''
SELECT #sql += ' Drop table ' + QUOTENAME(s.NAME) + '.' + QUOTENAME(t.NAME) + '; '
FROM sys.tables t
JOIN sys.schemas s
ON t.[schema_id] = s.[schema_id]
WHERE t.type = 'U'
Exec sp_executesql #sql
Note: If you have any foreign Keys defined between tables then first run the below query to disable all foreign keys present in your database.
EXEC sp_msforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"
For more information, check here.

Answer 2

If you want to use only one SQL query to delete all tables you can use this:
EXEC sp_MSforeachtable #command1 = "DROP TABLE ?"
This is a hidden Stored Procedure in sql server, and will be executed for each table in the database you're connected.
Note: You may need to execute the query a few times to delete all tables due to dependencies.
Note2: To avoid the first note, before running the query, first check if there foreign keys relations to any table. If there are then just disable foreign key constraint by running the query bellow:
EXEC sp_msforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"

Answer 3

If you don't want to type, you can create the statements with this:
USE Databasename
SELECT 'DROP TABLE [' + name + '];'
FROM sys.tables
Then copy and paste into a new SSMS window to run it.

Answer 4

The simplest way is to drop the whole database and create it once again:
drop database db_name
create database db_name
That's all.

Answer 5

You could also use the following script to drop everything, including the following:
non-system stored procedures
views
functions
foreign key constraints
primary key constraints
system_versioning
tables
https://michaelreichenbach.de/how-to-drop-everything-in-a-mssql-database/
/* Drop all non-system stored procs */
DECLARE #name VARCHAR(128)
DECLARE #SQL VARCHAR(254)
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'P' AND category = 0 ORDER BY [name])
WHILE #name is not null
BEGIN
SELECT #SQL = 'DROP PROCEDURE [dbo].[' + RTRIM(#name) +']'
EXEC (#SQL)
PRINT 'Dropped Procedure: ' + #name
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'P' AND category = 0 AND [name] > #name ORDER BY [name])
END
GO
/* Drop all views */
DECLARE #name VARCHAR(128)
DECLARE #SQL VARCHAR(254)
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'V' AND category = 0 ORDER BY [name])
WHILE #name IS NOT NULL
BEGIN
SELECT #SQL = 'DROP VIEW [dbo].[' + RTRIM(#name) +']'
EXEC (#SQL)
PRINT 'Dropped View: ' + #name
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'V' AND category = 0 AND [name] > #name ORDER BY [name])
END
GO
/* Drop all functions */
DECLARE #name VARCHAR(128)
DECLARE #SQL VARCHAR(254)
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] IN (N'FN', N'IF', N'TF', N'FS', N'FT') AND category = 0 ORDER BY [name])
WHILE #name IS NOT NULL
BEGIN
SELECT #SQL = 'DROP FUNCTION [dbo].[' + RTRIM(#name) +']'
EXEC (#SQL)
PRINT 'Dropped Function: ' + #name
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] IN (N'FN', N'IF', N'TF', N'FS', N'FT') AND category = 0 AND [name] > #name ORDER BY [name])
END
GO
/* Drop all Foreign Key constraints */
DECLARE #name VARCHAR(128)
DECLARE #constraint VARCHAR(254)
DECLARE #SQL VARCHAR(254)
SELECT #name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' ORDER BY TABLE_NAME)
WHILE #name is not null
BEGIN
SELECT #constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' AND TABLE_NAME = #name ORDER BY CONSTRAINT_NAME)
WHILE #constraint IS NOT NULL
BEGIN
SELECT #SQL = 'ALTER TABLE [dbo].[' + RTRIM(#name) +'] DROP CONSTRAINT [' + RTRIM(#constraint) +']'
EXEC (#SQL)
PRINT 'Dropped FK Constraint: ' + #constraint + ' on ' + #name
SELECT #constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' AND CONSTRAINT_NAME <> #constraint AND TABLE_NAME = #name ORDER BY CONSTRAINT_NAME)
END
SELECT #name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' ORDER BY TABLE_NAME)
END
GO
/* Drop all Primary Key constraints */
DECLARE #name VARCHAR(128)
DECLARE #constraint VARCHAR(254)
DECLARE #SQL VARCHAR(254)
SELECT #name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' ORDER BY TABLE_NAME)
WHILE #name IS NOT NULL
BEGIN
SELECT #constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' AND TABLE_NAME = #name ORDER BY CONSTRAINT_NAME)
WHILE #constraint is not null
BEGIN
SELECT #SQL = 'ALTER TABLE [dbo].[' + RTRIM(#name) +'] DROP CONSTRAINT [' + RTRIM(#constraint)+']'
EXEC (#SQL)
PRINT 'Dropped PK Constraint: ' + #constraint + ' on ' + #name
SELECT #constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' AND CONSTRAINT_NAME <> #constraint AND TABLE_NAME = #name ORDER BY CONSTRAINT_NAME)
END
SELECT #name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY KEY' ORDER BY TABLE_NAME)
END
GO
/* Remove system versioning */
DECLARE #name VARCHAR(128)
DECLARE #SQL VARCHAR(254)
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 ORDER BY [name])
WHILE #name IS NOT NULL
BEGIN
IF OBJECTPROPERTY(OBJECT_ID(' + #name + '), 'TableTemporalType') = 2
SELECT #SQL = 'ALTER TABLE [dbo].[' + RTRIM(#name) +'] SET (SYSTEM_VERSIONING = OFF); ALTER TABLE [dbo].[' + RTRIM(#name) + '] DROP PERIOD FOR SYSTEM_TIME;'
EXEC (#SQL)
PRINT 'System Versioning Disabled for Table: ' + #name
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 AND [name] > #name ORDER BY [name])
END
GO
/* Drop all tables */
DECLARE #name VARCHAR(128)
DECLARE #SQL VARCHAR(254)
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 ORDER BY [name])
WHILE #name IS NOT NULL
BEGIN
SELECT #SQL = 'DROP TABLE [dbo].[' + RTRIM(#name) +']'
EXEC (#SQL)
PRINT 'Dropped Table: ' + #name
SELECT #name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 AND [name] > #name ORDER BY [name])
END
GO

Answer 6

As a follow-up to Dave.Gugg's answer, this would be the code someone would need to get all the DROP TABLE lines in MySQL:
SELECT CONCAT('DROP TABLE ', TABLE_NAME, ';')
FROM INFORMATION_SCHEMA.tables
WHERE TABLE_SCHEMA = 'your_database_name'

Answer 7

I'd just make a small change to #NoDisplayName's answer and use QUOTENAME() on the TABLE_NAME column and also include the TABLE_SCHEMA column encase the tables aren't in the dbo schema.
DECLARE #sql nvarchar(max) = '';
SELECT #sql += 'DROP TABLE ' + QUOTENAME([TABLE_SCHEMA]) + '.' + QUOTENAME([TABLE_NAME]) + ';'
FROM [INFORMATION_SCHEMA].[TABLES]
WHERE [TABLE_TYPE] = 'BASE TABLE';
EXEC SP_EXECUTESQL #sql;
Or using sys schema views (as per #swasheck's comment):
DECLARE #sql nvarchar(max) = '';
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].[type] = 'U' AND [T].[is_ms_shipped] = 0;
EXEC SP_EXECUTESQL #sql;

Answer 8

If anybody else had a problem with best answer's solution (including disabling foreign keys), here is another solution from me:
-- CLEAN DB
USE [DB_NAME]
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
EXEC sp_MSForEachTable 'DELETE FROM ?'
DECLARE #Sql NVARCHAR(500) DECLARE #Cursor CURSOR
SET #Cursor = CURSOR FAST_FORWARD FOR
SELECT DISTINCT sql = 'ALTER TABLE [' + tc2.TABLE_NAME + '] DROP [' + rc1.CONSTRAINT_NAME + ']'
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc1
LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc2 ON tc2.CONSTRAINT_NAME =rc1.CONSTRAINT_NAME
OPEN #Cursor FETCH NEXT FROM #Cursor INTO #Sql
WHILE (##FETCH_STATUS = 0)
BEGIN
Exec SP_EXECUTESQL #Sql
FETCH NEXT
FROM #Cursor INTO #Sql
END
CLOSE #Cursor DEALLOCATE #Cursor
GO
EXEC sp_MSForEachTable 'DROP TABLE ?'
GO
EXEC sp_MSForEachTable 'ALTER TABLE ? WITH CHECK CHECK CONSTRAINT ALL'

Answer 9

Not quite 1 query, still quite short and sweet:
-- Disable all referential integrity constraints
EXEC sp_msforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
GO
-- Drop all PKs and FKs
declare #sql nvarchar(max)
SELECT #sql = STUFF((SELECT '; ' + 'ALTER TABLE ' + Table_Name +' drop constraint ' + Constraint_Name from Information_Schema.CONSTRAINT_TABLE_USAGE ORDER BY Constraint_Name FOR XML PATH('')),1,1,'')
EXECUTE (#sql)
GO
-- Drop all tables
EXEC sp_msforeachtable 'DROP TABLE ?'
GO

Answer 10

Use the following script to drop all constraints:
DECLARE #sql NVARCHAR(max)=''
SELECT #sql += ' ALTER TABLE ' + QUOTENAME(TABLE_SCHEMA) + '.'+ QUOTENAME(TABLE_NAME) + ' NOCHECK CONSTRAINT all; '
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
Exec Sp_executesql #sql
Then run the following to drop all tables:
select #sql='';
SELECT #sql += ' Drop table ' + QUOTENAME(TABLE_SCHEMA) + '.'+ QUOTENAME(TABLE_NAME) + '; '
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
Exec Sp_executesql #sql
This worked for me in Azure SQL Database where 'sp_msforeachtable' was not available!

Answer 11

I Know this question is very old but every Time i need this code .. by the way if you have tables and views and Functions and PROCEDURES you can delete it all by this Script ..
so why i post this Script ?? because if u delete all tables you will need to delete all views and if you have Functions and PROCEDURES you need to delete it too
i Hope it will help someone
DECLARE #sql NVARCHAR(max)=''
SELECT #sql += ' Drop table ' + QUOTENAME(TABLE_SCHEMA) + '.'+ QUOTENAME(TABLE_NAME)
+ '; '
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
Exec Sp_executesql #sql
DECLARE #sql VARCHAR(MAX) = ''
, #crlf VARCHAR(2) = CHAR(13) + CHAR(10) ;
SELECT #sql = #sql + 'DROP VIEW ' + QUOTENAME(SCHEMA_NAME(schema_id)) + '.' +
QUOTENAME(v.name) +';' + #crlf
FROM sys.views v
PRINT #sql;
EXEC(#sql);
declare #procName varchar(500)
declare cur cursor
for select [name] from sys.objects where type = 'p'
open cur
fetch next from cur into #procName
while ##fetch_status = 0
begin
exec('drop procedure [' + #procName + ']')
fetch next from cur into #procName
end
close cur
deallocate cur
Declare #sql NVARCHAR(MAX) = N'';
SELECT #sql = #sql + N' DROP FUNCTION '
+ QUOTENAME(SCHEMA_NAME(schema_id))
+ N'.' + QUOTENAME(name)
FROM sys.objects
WHERE type_desc LIKE '%FUNCTION%';
Exec sp_executesql #sql
GO

Answer 12

Try this
DROP DATABASE database_name;
CREATE DATABASE database_name;
This will delete the database and create a new database with the same name

Answer 13

I‘d do it with a loop for all tables if you’re using like oracle or sqlite:
FOR i IN (SELECT ut.table_name
FROM USER_TABLES ut) LOOP
EXECUTE IMMEDIATE 'drop table '|| i.table_name ||' CASCADE CONSTRAINTS ';
END LOOP;

Answer 14

For me I just do
DECLARE #cnt INT = 0;
WHILE #cnt < 10 --Change this if all tables are not dropped with one run
BEGIN
SET #cnt = #cnt + 1;
EXEC sp_MSforeachtable #command1 = "DROP TABLE ?"
END