MS SQL Commands: A Cheat Sheet for Developers

Are you an experienced developer in need of quick MS SQL command references? This article presents to you the cheat sheet for developers. It covers the basics of creating and displaying databases and tables. Also, these commands modify the table and the fundamental syntax for T-SQL commands like SELECT, INSERT, UPDATE, and DELETE.  Before that, let’s decode what MS SQL commands and their categories.

MS SQL Commands: A Quick Introduction

MS SQL commands are the backbone of managing and interacting with databases in the Microsoft SQL server.  These commands are categorized into different groups like Data Definition Language (DDL), Data Manipulation Language (DML), and Data Query Language (DQL), each serving a purpose. For example, DDL commands like CREATE, ALTER and DROP help define and modify the database structures. On the other hand, DML commands like INSERT, UPDATE, and DELETE allow users to manipulate the data within tables. 

One of the most commonly used MS SQL commands is the SELECT command, which belongs to the DQL category. This command is pivotal for retrieving data from one or more tables based on specific criteria. It allows users to filter and sort the aggregate data, making it an indispensable tool for generating reports and insights. By mastering the SELECT command and other SQL queries, users can effectively harness the power of MS SQL Server to access and analyze their data.

MS SQL commands also include Transaction Control Language (TCL) commands like COMMIT, ROLLBACK, and SAVEPOINT, which are crucial for managing transactions within a database. These commands ensure data integrity by allowing users to control the execution of multiple SQL commands as a single unit. 

Popular MS SQL Commands

Here are the most popular MS SQL commands every developer must execute in their web projects. 

Data Definition Language (DDL) Commands:

• CREATE: Creates a new database, table, index, or view.
  • Example: CREATE TABLE Employees (ID int, Name varchar(255));
• ALTER: Modifies an existing database object like a table.
  • Example: ALTER TABLE Employees ADD DateOfBirth date;
• DROP: Deletes an existing database, table, index, or view.
  • Example: DROP TABLE Employees;
• TRUNCATE: Removes all rows from a table without logging the individual row deletions.
  • Example: TRUNCATE TABLE Employees;

Data Manipulation Language (DML) Commands:

• SELECT: Retrieves data from one or more tables.
  • Example: SELECT * FROM Employees;
• INSERT: Adds new rows to a table.
  • Example: INSERT INTO Employees (ID, Name) VALUES (1, ‘John Doe’);
• UPDATE: Modifies existing rows in a table.
  • Example: UPDATE Employees SET Name = ‘Jane Doe’ WHERE ID = 1;
• DELETE: Removes rows from a table.
  • Example: DELETE FROM Employees WHERE ID = 1;

Data Control Language (DCL) Commands:

• GRANT: Gives a user permission to perform actions on the database.
  • Example: GRANT SELECT ON Employees TO UserName;
• REVOKE: Removes a user’s permissions on the database.
  • Example: REVOKE SELECT ON Employees FROM UserName;

Transaction Control Language (TCL) Commands:

• BEGIN TRANSACTION: Starts a new transaction.
  • Example: BEGIN TRANSACTION;
• COMMIT: Saves the changes made during the transaction.
  • Example: COMMIT;
• ROLLBACK: Reverts the changes made during the transaction.
  • Example: ROLLBACK;
• SAVEPOINT: Sets a savepoint within a transaction.
  • Example: SAVEPOINT SavePoint1;
• ROLLBACK TO SAVEPOINT: Rolls back the transaction to a specific savepoint.
  • Example: ROLLBACK TO SavePoint1;

Benefits of MS SQL Commands

Using MS SQL commands offers several benefits that enhance database management’s efficiency, security, and performance. Here are the key advantages:

1. Efficient Data Management

• Data Retrieval: Commands like SELECT, WHERE, and JOIN enable precise data retrieval, allowing you to extract exactly the information you need from large datasets quickly.
• Data Manipulation: With commands like INSERT, UPDATE, and DELETE, you can efficiently manage the data by adding, modifying, or removing records as needed. 

2. Enhanced Security

• Access Control: DCL commands like GRANT and REVOKE allow you to manage user permissions, ensuring that only authorized users can access or modify the data.
• Transaction Management: TCL commands (BEGIN TRANSACTION, COMMIT, ROLLBACK) ensure data integrity by allowing controlled data changes, reducing the risk of accidental data loss or corruption.

3. Improved Data Integrity

• Atomic Transactions: Using transactions ensures that operations are completed fully or not at all, maintaining database consistency and preventing partial updates.
• Constraints: Commands like ALTER allow you to enforce data integrity rules, such as foreign keys or unique constraints, ensuring that data remains accurate and reliable.

4. Flexibility in Querying

• Complex Queries: MS SQL commands like JOIN, UNION, and SUBQUERY enable complex querying, allowing you to combine and filter data from multiple tables or even other queries.
• Conditional Logic: The CASE command allows you to implement conditional logic directly within SQL queries, enabling dynamic data processing.

5. Performance Optimization

• Indexing: Commands like CREATE INDEX can significantly enhance query performance by reducing the time it takes to retrieve data from large tables.
• Efficient Sorting and Grouping: ORDER BY, GROUP BY and HAVING commands help in organizing and filtering data efficiently, enhancing readability and processing speed. 

6. Scalability

• Handling Large Datasets: MS SQL commands are designed to efficiently handle and manipulate large datasets, making it easier to scale your operations as your data grows.
• Batch Processing: Commands can be executed in batches, allowing for the efficient handling of large numbers of transactions or operations.

7. Ease of Use and Integration

• Standardized Syntax: MS SQL commands follow a standardized SQL syntax, making it easier for database administrators and developers to learn and use.
• Integration with Other Systems: MS SQL commands can be easily integrated into various applications and systems, enhancing the database’s interoperability with other technologies.

8. Data Consistency and Reliability

• Rollback Capability: In case of an error or issue during a transaction, the ability to ROLLBACK ensures that the database remains in a consistent state.
• Version Control: By using SAVEPOINT within transactions, you can manage changes at different stages, further ensuring the reliability of data updates. 

9. Automation and Scripting

• Automated Tasks: MS SQL commands can be scripted and scheduled, automating repetitive database tasks such as backups, updates, and maintenance.
• Dynamic Data Management: You can create dynamic queries and scripts that adjust to different data conditions and requirements, streamlining database operations.

10. Comprehensive Reporting

• Aggregated Data: Commands like GROUP BY, COUNT, SUM, and AVG allow for powerful data aggregation, enabling comprehensive reporting and analytics.
• Custom Views: With the VIEW command, you can create custom views of the data customized to specific reporting needs without altering the tables.