aportes sql server

Cursores/Cursor_English.sql

@@ -0,0 +1,89 @@
+USE AdventureWorks2019;
+GO
+
+-- Declare the variables to be used
+DECLARE @c TINYINT = 1, @a TINYINT = 1
+    , @businessEntityID INT
+    , @creditCardID INT
+    , @modifiedDate DATETIME
+    , @cardType VARCHAR(100)
+    , @cardNumber VARCHAR(25)
+    , @expMonth TINYINT
+    , @expYear SMALLINT
+    , @modifiedDate2 DATETIME;
+
+-- Declare the cursor for PersonCreditCard
+DECLARE cPersonCreditCard CURSOR FOR
+SELECT TOP 20 BusinessEntityID, CreditCardID, ModifiedDate
+FROM Sales.PersonCreditCard; -- Ensure this table exists
+
+-- Open the PersonCreditCard cursor
+OPEN cPersonCreditCard;
+
+-- Fetch the first row from the cursor
+FETCH NEXT FROM cPersonCreditCard
+INTO @businessEntityID, @creditCardID, @modifiedDate;
+
+-- Iterate through the rows of the PersonCreditCard cursor
+WHILE @@FETCH_STATUS = 0
+BEGIN
+    -- Print the values for the current row
+    PRINT '< Cursor cPersonCreditCard: ' + CAST(@c AS VARCHAR);
+    PRINT '@businessEntityID: ' + CAST(@businessEntityID AS VARCHAR);
+    PRINT '@creditCardID: ' + CAST(@creditCardID AS VARCHAR);
+    PRINT '@modifiedDate: ' + CAST(@modifiedDate AS VARCHAR);
+
+    SET @c = @c + 1;
+    SET @a = 1;
+
+    -- Declare a nested cursor for CreditCard
+    DECLARE cCreditCard CURSOR FOR
+    SELECT CardType, CardNumber, ExpMonth, ExpYear, ModifiedDate
+    FROM Sales.CreditCard
+    WHERE CreditCardID = @creditCardID; -- Ensure this table exists
+
+    -- Open the CreditCard cursor
+    OPEN cCreditCard;
+
+    -- Fetch the first row from the CreditCard cursor
+    FETCH NEXT FROM cCreditCard
+    INTO @cardType, @cardNumber, @expMonth, @expYear, @modifiedDate2;
+
+    -- Iterate through the rows of the CreditCard cursor
+    WHILE @@FETCH_STATUS = 0
+    BEGIN
+        -- Print the values for the current row of the CreditCard cursor
+        PRINT '   <<< Cursor cCreditCard: ' + CAST(@a AS VARCHAR);
+        PRINT '   @cardType: ' + CAST(@cardType AS VARCHAR);
+        PRINT '   @cardNumber: ' + CAST(@cardNumber AS VARCHAR);
+        PRINT '   @expMonth: ' + CAST(@expMonth AS VARCHAR);
+        PRINT '   @expYear: ' + CAST(@expYear AS VARCHAR);
+        PRINT '   @modifiedDate2: ' + CAST(@modifiedDate2 AS VARCHAR);
+        PRINT '   >>>>>';
+
+        SET @a = @a + 1;
+        -- Fetch the next row from the CreditCard cursor
+        FETCH NEXT FROM cCreditCard
+        INTO @cardType, @cardNumber, @expMonth, @expYear, @modifiedDate2;
+    END -- End of the CreditCard cursor iteration
+
+    CLOSE cCreditCard; -- Close the CreditCard cursor
+    DEALLOCATE cCreditCard; -- Deallocate the CreditCard cursor
+
+    PRINT '>>>>>>>>';
+
+    -- Fetch the next row from the PersonCreditCard cursor
+    FETCH NEXT FROM cPersonCreditCard
+    INTO @businessEntityID, @creditCardID, @modifiedDate;
+END -- End of the PersonCreditCard cursor iteration
+
+CLOSE cPersonCreditCard; -- Close the PersonCreditCard cursor
+DEALLOCATE cPersonCreditCard; -- Deallocate the PersonCreditCard cursor
+
+Key Points:
+
+    Cursor Declaration: The DECLARE cPersonCreditCard CURSOR FOR section defines the cursor to iterate through rows from the Sales.PersonCreditCard table.
+    Cursor Operations: The OPEN, FETCH NEXT, CLOSE, and DEALLOCATE commands manage the lifecycle of the cursor, fetching and processing rows as needed.
+    Nested Cursor: The nested cursor cCreditCard is used to fetch related card details based on CreditCardID.
+
+Make sure to validate that Sales.PersonCreditCard and Sales.CreditCard exist in your AdventureWorks 2019 database and that the column names match those used in the script.

Indexacion/Indexation.sql

@@ -0,0 +1,71 @@
+-- Use the AdventureWorks2019 database
+USE AdventureWorks2019;
+GO
+
+-- ================================================
+-- Indexing Example
+-- ================================================
+
+-- Create a non-clustered index on the 'Name' column of the 'Product' table
+-- This will help improve performance for queries that filter or sort by 'Name'
+CREATE NONCLUSTERED INDEX IX_Product_Name
+ON Production.Product (Name);
+GO
+
+-- Verify that the index has been created
+-- This query retrieves information about the 'IX_Product_Name' index
+SELECT * 
+FROM sys.indexes 
+WHERE object_id = OBJECT_ID('Production.Product') 
+AND name = 'IX_Product_Name';
+GO
+
+-- View index usage statistics
+-- This query shows how often the index is used by looking at statistics
+SELECT * 
+FROM sys.dm_db_index_usage_stats 
+WHERE object_id = OBJECT_ID('Production.Product');
+GO
+
+-- ================================================
+-- Blocking Example
+-- ================================================
+
+-- Display current blocking information
+-- This query shows details about sessions that are blocking other sessions
+SELECT 
+    blocking_session_id AS BlockingSessionID, -- ID of the session causing the block
+    session_id AS BlockedSessionID,           -- ID of the session being blocked
+    wait_type,                                -- Type of wait for the blocked session
+    wait_time,                                -- Time the blocked session has been waiting
+    wait_resource                             -- Resource causing the wait
+FROM sys.dm_exec_requests
+WHERE blocking_session_id <> 0;
+GO
+
+-- Investigate details of blocking transactions
+-- This query provides more information about sessions and transactions involved in blocking
+SELECT 
+    r.session_id,
+    r.blocking_session_id,
+    r.wait_type,
+    r.wait_time,
+    r.wait_resource,
+    s.login_name,
+    s.host_name,
+    t.transaction_state
+FROM sys.dm_exec_requests r
+JOIN sys.dm_exec_sessions s ON r.session_id = s.session_id
+JOIN sys.dm_tran_session_transactions t ON r.session_id = t.session_id
+WHERE r.blocking_session_id <> 0;
+GO
+
+-- ================================================
+-- Terminate a blocking session (Use with caution!)
+-- ================================================
+
+-- To forcefully terminate a blocking session, replace <session_id> with the actual session ID
+-- This should be done carefully as it will terminate the session and rollback any uncommitted transactions
+-- Example: KILL 55;
+KILL <session_id>;
+GO

README.md

@@ -5,6 +5,7 @@
 - [Guia de estudio](#guia-de-estudio)
 - [Herramientas](#herramientas)
 
+
 # Guia de estudio
 
 Publicaciones:
@@ -53,6 +54,8 @@ Publicaciones:
 - Visual Studio Code - [Descarga](https://code.visualstudio.com/download)
   - Extensiones: [SQL Tools](https://marketplace.visualstudio.com/items?itemName=mtxr.sqltools), [Bicep](https://marketplace.visualstudio.com/items?itemName=ms-azuretools.vscode-bicep), [Markdown](https://marketplace.visualstudio.com/items?itemName=yzhang.markdown-all-in-one), [Powershell](https://marketplace.visualstudio.com/items?itemName=ms-vscode.PowerShell)
   - [Teclas rápidas](png/keyboard-shortcuts-windows.pdf), [teclas rápidas (2)](https://www.sitepoint.com/visual-studio-code-keyboard-shortcuts/)
+- SQL Server Basics - [SqlServer](https://www.sqlshack.com/sql-server-training/)
+