50 Consultas importantes en SQL Server

En este artículo voy a explicar algunas consultas de propósito general. Creo que cada desarrollador debe tener conocimiento de estas consultas.

Estas consultas no están relacionados con cualquier tema específico de SQL . Pero el conocimiento de este tipo de consultas puede resolver algunas tareas complejas y puede ser utilizado en muchos escenarios, así que decidí escribir un artículo sobre estas consultas.

Query 1: Retrieve List of All Database

1. EXEC sp_helpdb  

Example:

Query 2: Display Text of Stored Procedure, Trigger, View

1. exec sp_helptext @objname = 'Object_Name'  

Example:

Query 3: Get All Stored Procedure Relate To Database

1. SELECT DISTINCT o.name, o.xtype  
2.   
3. FROM syscomments c  
4.   
5. INNER JOIN sysobjects o ON c.id=o.id  
6.   
7. WHERE o.xtype='P'  

Example:

To retrieve the View use “V” instead of “P” and for functions use “FN.

Query 4: Get All Stored Procedure Relate To Table

1. SELECT DISTINCT o.name, o.xtype  
2.   
3. FROM syscomments c  
4.   
5. INNER JOIN sysobjects o ON c.id=o.id  
6.   
7. WHERE c.TEXT LIKE '%Table_Name%' AND o.xtype='P'  

Example:

To retrieve the View use “V” instead of “P” and for functions use “FN.

Query 5: Rebuild All Index of Database

1. EXEC sp_MSforeachtable @command1="print '?' DBCC DBREINDEX ('?', ' ', 80)"  
2.   
3. GO  
4.   
5. EXEC sp_updatestats  
6.   
7. GO  

Example:

Query 6: Retrieve All dependencies of Stored Procedure:

This query return all objects name that are using into stored procedure like table, user define function, another stored procedure.

Query:

1. ;WITH stored_procedures AS (  
2.   
3. SELECT  
4.   
5. oo.name AS table_name,  
6.   
7. ROW_NUMBER() OVER(partition by o.name,oo.name ORDER BY o.name,oo.name) AS row  
8.   
9. FROM sysdepends d  
10.   
11. INNER JOIN sysobjects o ON o.id=d.id  
12.   
13. INNER JOIN sysobjects oo ON oo.id=d.depid  
14.   
15. WHERE o.xtype = 'P' AND o.name LIKE '%SP_NAme%' )  
16.   
17. SELECT Table_name FROM stored_procedures  
18.   
19. WHERE row = 1  

Example:

Query 7: Find Byte Size Of All tables in database

1. SELECT sob.name AS Table_Name,  
2.   
3. SUM(sys.length) AS [Size_Table(Bytes)]  
4.   
5. FROM sysobjects sob, syscolumns sys  
6.   
7. WHERE sob.xtype='u' AND sys.id=sob.id  
8.   
9. GROUP BY sob.name  

Example:

Query 8: Get all table that don’t have identity column:

Query:

1. SELECT  
2.   
3. TABLE_NAME FROM INFORMATION_SCHEMA.TABLES  
4.   
5. where  
6.   
7. Table_NAME NOT IN  
8.   
9. (  
10.   
11. SELECT DISTINCT c.TABLE_NAME FROM INFORMATION_SCHEMA.COLUMNS c  
12.   
13. INNER  
14.   
15. JOIN sys.identity_columns ic  
16.   
17. on  
18.   
19. (c.COLUMN_NAME=ic.NAME))  
20.   
21. AND  
22.   
23. TABLE_TYPE ='BASE TABLE'  

Example:

Query 9: List of Primary Key and Foreign Key for Whole Database

1. SELECT  
2.   
3. DISTINCT  
4.   
5. Constraint_Name AS [Constraint],  
6.   
7. Table_Schema AS [Schema],  
8.   
9. Table_Name AS [TableName] FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE  
10.   
11. GO  

Example:

Query 10: List of Primary Key and Foreign Key for a particular table

1. SELECT  
2.   
3. DISTINCT  
4.   
5. Constraint_Name AS [Constraint],  
6.   
7. Table_Schema AS [Schema],  
8.   
9. Table_Name AS [TableName] FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE  
10.   
11. WHERE INFORMATION_SCHEMA.KEY_COLUMN_USAGE.TABLE_NAME='Table_Name'  
12.   
13. GO  

Example:

Query 11: RESEED Identity of all tables

1. EXEC sp_MSForEachTable '  
2.   
3. IF OBJECTPROPERTY(object_id(''?''), ''TableHasIdentity'') = 1  
4.   
5. DBCC CHECKIDENT (''?'', RESEED, 0)  

Example:

Query 12: List of tables with number of records

1. CREATE TABLE #Tab  
2.   
3. (  
4.   
5. Table_Name [varchar](max),  
6.   
7. Total_Records int  
8.   
9. );  
10.   
11. EXEC sp_MSForEachTable @command1=' Insert Into #Tab(Table_Name, Total_Records) SELECT ''?'', COUNT(*) FROM ?'  
12.   
13. SELECT * FROM #Tab t ORDER BY t.Total_Records DESC;  
14.   
15. DROP TABLE #Tab;  

Example:

Query 13: Get the version name of SQL Server

1. SELECT @@VERSION AS Version_Name  

Example:

Query 14: Get Current Language of SQL Server

1. SELECT @@LANGUAGE AS Current_Language;  

Example:

Query 15: Disable all constraints of a table

1. ALTER TABLE Table_Name NOCHECK CONSTRAINT ALL  

Example:

Query16: Disable all constraints of all tables

1. EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'  

Example:

Query 17: Get Current Language Id

1. SELECT @@LANGID AS 'Language ID'  

Example:

Query18: Get precision level used by decimal and numeric as current set in Server:

1. SELECT @@MAX_PRECISION AS 'MAX_PRECISION'  

Example:

Query 19: Return Server Name of SQL Server

1. SELECT @@SERVERNAME AS 'Server_Name'  

Example:

Query 20: Get name of register key under which SQL Server is running

1. SELECT @@SERVICENAME AS 'Service_Name'  

Example:

Query 21: Get Session Id of current user process

1. SELECT @@SPID AS 'Session_Id'  

Example:

Query22: Get Current Value of TEXTSIZE option

1. SELECT @@TEXTSIZE AS 'Text_Size'  

Example:

Query 23: Retrieve Free Space of Hard Disk

1. EXEC master..xp_fixeddrives  

Example:

Query24: Disable a Particular Trigger

Syntax:

1. ALTER TABLE Table_Name DISABLE TRIGGER Trigger_Name  

Example:

1. ALTER TABLE Employee DISABLE TRIGGER TR_Insert_Salary  

Query 25: Enable a Particular Trigger

Syntax:

1. ALTER TABLE Table_Name ENABLE TRIGGER Trigger_Name  

Example:

1. ALTER TABLE Employee ENABLE TRIGGER TR_Insert_Salary  

Query 26: Disable All Trigger of a table

We can disable and enable all triggers of a table using previous query, but replacing the "ALL" instead of trigger name.
Syntax:

1. ALTER TABLE Table_Name DISABLE TRIGGER ALL  

Example:

1. ALTER TABLE Demo DISABLE TRIGGER ALL  

Query 27: Enable All Trigger of a table

1. ALTER TABLE Table_Name ENABLE TRIGGER ALL  

Example:

1. ALTER TABLE Demo ENABLE TRIGGER ALL  

Query 28: Disable All Trigger for database

Using sp_msforeachtable system stored procedure we enable and disable all triggers for a database.

Syntax:

1. Use Database_Name  
2.   
3. Exec sp_msforeachtable "ALTER TABLE ? DISABLE TRIGGER all"  

Example:

Query29: Enable All Trigger for database

1. Use Demo  
2.   
3. Exec sp_msforeachtable "ALTER TABLE ? ENABLE TRIGGER all"  

Example:

Query30: List of Stored procedure modified in last N days

1. SELECT name,modify_date  
2.   
3. FROM sys.objects  
4.   
5. WHERE type='P'  
6.   
7. AND DATEDIFF(D,modify_date,GETDATE())< N  

Example:

Query31: List of Stored procedure created in last N days

1. SELECT name,sys.objects.create_date  
2.   
3. FROM sys.objects  
4.   
5. WHERE type='P'  
6.   
7. AND DATEDIFF(D,sys.objects.create_date,GETDATE())< N  

Example:

Query32: Recompile a stored procedure

1. EXEC sp_recompile'Procedure_Name';  
2.   
3. GO  

Example:

Query 33: Recompile all stored procedure on a table

1. EXEC sp_recompile N'Table_Name';  
2.   
3. GO  

Example:

Query 34: Get all columns of a specific data type:

Query:

1. SELECT OBJECT_NAME(c.OBJECT_ID) as Table_Name, c.name as Column_Name  
2.   
3. FROM sys.columns AS c  
4.   
5. JOIN sys.types AS t ON c.user_type_id=t.user_type_id  
6.   
7. WHERE t.name = 'Data_Type'  

Example:

Query 35: Get all Nullable columns of a table

1. SELECT OBJECT_NAME(c.OBJECT_ID) as Table_Name, c.name as Column_Name  
2.   
3. FROM sys.columns AS c  
4.   
5. JOIN sys.types AS t ON c.user_type_id=t.user_type_id  
6.   
7. WHERE c.is_nullable=0 AND OBJECT_NAME(c.OBJECT_ID)='Table_Name'  

Example:

Query 36: Get All table that don’t have primary key

1. SELECT name AS Table_Name  
2.   
3. FROM sys.tables  
4.   
5. WHERE OBJECTPROPERTY(OBJECT_ID,'TableHasPrimaryKey') = 0  
6.   
7. ORDER BY Table_Name;  

Example:

Query 37: Get All table that don’t have foreign key

1. SELECT name AS Table_Name  
2.   
3. FROM sys.tables  
4.   
5. WHERE OBJECTPROPERTY(OBJECT_ID,'TableHasForeignKey') = 0  
6.   
7. ORDER BY Table_Name;  

Example:

Query 38: Get All table that don’t have identity column

1. SELECT name AS Table_Name  
2.   
3. FROM sys.tables  
4.   
5. WHERE OBJECTPROPERTY(OBJECT_ID,'TableHasIdentity') = 0  
6.   
7. ORDER BY Table_Name;  

Example:

Query 39: Get First Date of Current Month

1. SELECT CONVERT(VARCHAR(25),DATEADD(DAY,-(DAY(GETDATE()))+1,GETDATE()),105) First_Date_Current_Month;  

Example:

Query 40: Get last date of previous month

1. SELECT CONVERT(VARCHAR(25),DATEADD(DAY,-(DAY(GETDATE())),GETDATE()),105) Last_Date_Previous_Month;  

Example:

Query 41: Get last date of current month

1. SELECT CONVERT(VARCHAR(25),DATEADD(DAY,-(DAY(GETDATE())), DATEADD(MONTH,1,GETDATE())),105) Last_Date_Current_Month;  

Example:

Query 42: Get first date of next month

1. SELECT CONVERT(VARCHAR(25),DATEADD(DAY,-(DAY(GETDATE())), DATEADD(MONTH,1,GETDATE())+1),105) First_Date_Next_Month;  

Example:

Query 43: Swap the values of two columns

1. UPDATE Table_Name SET Column1=Column2, Column2=Column1  

Example:

Query 44: Remove all stored procedure from database

1. Declare @Drop_SP Nvarchar(MAX)  
2.   
3. Declare My_Cursor Cursor For Select [name] From sys.objects where type = 'p'  
4.   
5. Open My_Cursor  
6.   
7. Fetch Next From My_Cursor Into @Drop_SP  
8.   
9. While @@FETCH_STATUS= 0  
10.   
11. Begin  
12.   
13. Exec('DROP PROCEDURE ' + @Drop_SP)  
14.   
15. Fetch Next From My_Cursor Into @Drop_SP  
16.   
17. End  
18.   
19. Close My_Cursor  
20.   
21. Deallocate My_Cursor  

Example:

Query 45: Remove all views from database

1. Declare @Drop_View Nvarchar(MAX)  
2.   
3. Declare My_Cursor Cursor For Select [name] From sys.objects where type = 'v'  
4.   
5. Open My_Cursor  
6.   
7. Fetch Next From My_Cursor Into @Drop_View  
8.   
9. While @@FETCH_STATUS = 0  
10.   
11. Begin  
12.   
13. Exec('DROP VIEW ' + @Drop_View)  
14.   
15. Fetch Next From My_Cursor Into @Drop_View  
16.   
17. End  
18.   
19. Close My_Cursor  
20.   
21. Deallocate My_Cursor  

Example:

Query 46: Drop all tables

1. EXEC sys.sp_MSforeachtable @command1 = 'Drop Table ?'  

Example:

Query 47: Get information of tables’ columns

1. SELECT * FROM INFORMATION_SCHEMA.COLUMNS  
2.   
3. WHERE INFORMATION_SCHEMA.COLUMNS.TABLE_NAME=’Table_Name’  

Example:

Query 48: Get all columns contain any constraints

1. SELECT TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE  

Example:

Query 49: Get all tables that contain a view

1. SELECT * FROM INFORMATION_SCHEMA.VIEW_TABLE_USAGE  

Example:

Query 50: Get all columns of table that using in views

1. SELECT * FROM INFORMATION_SCHEMA.VIEW_COLUMN_USAGE  

Example:

Leer entrada original en http://www.c-sharpcorner.com/article/50-important-queries-in-sql-server/