SQL statements are atomic units of work. So, they either completely fail or completely succeed. It is a set of instructions consisting of parameters, identifiers, variables, data types, names, and SQL reserved words that compile successfully. Data analysts create transactions for SQL statements if a command does not implicitly specify the commencement of a transaction. Analytical services commit implicit transactions if the statement is successful, and roll back implicit transactions if it fails.
SQL Statements – Multiple If and Other
SQL statements can be of various types, especially if you are dealing with e-commerce transactions. However, the most important is a SELECT statement that retrieves rows from the database and enables the selection of rows or columns from one or more tables in SQL Server. Let us explore the categories of statements that you can us including multiple if statements and the SELECT statement.
Case Sensitive Statements
The SQL statements are case-insensitive. So, you can get statements like SELECT, WHERE, multiple if, etc. However, MySQL offers an option to enable/disable the case sensitivity aspect. Table and column names are usually case-sensitive on Linux MySQL and case-insensitive on Windows.
Statements in SQL Server
- Backup and Restore
The Backup and Restore statement offers a way to create backups and also restore data from backups.
- Data Defining Statement
Data Definition Language (DDL) statements are used to define data structure. This is very significant especially when you are dealing with a trove of data in an eCommerce scenario. You can use these statements to create, alter, and drop data structures in a database. Some of these statements are ALTER, Collations, CREATE, DROP, DISABLE TRIGGER, ENABLE TRIGGER, RENAME, UPDATE STATISTICS, TRUNCATE TABLE
- Data Manipulating Statement
Data Manipulating statements act on data stored in the database. You can use these statements to update, insert, and change the rows in a database. These include – BULK INSERT, DELETE, SELECT, INSERT, UPDATE, MERGE.
- Permissions statements
Permissions statements let users access data and perform operations.
- Service Broker statements
Service Broker statements provide support in messaging and queuing apps.
You can use if statements to test various conditions in SQL. To use several if statements you need to use an ELSE statement. If the number of conditions to test is more than two, you need to nest the IF statements. So, it goes like this – IF….ELSE IF….ELSE.
Better Way To Test Multiple Conditions
You can surely go for multiple if statements, but a better statement can be written with CASE WHEN. You can use a CASE WHEN statement instead of an IF statement to test multiple conditions. This is a better way to test multiple conditions as it creates SQL queries are easier.
If you are using business intelligence systems like power bi, you need to make sure that you are aware of the full potential of the system. DAX in Power BI and similar libraries in other business intelligence systems let you operate several functions. However, you need to have a very good idea of SQL server if you need to manipulate data in the database