How to Use IF...THEN Logic in SQL Server | Atlassian (2024)

FAQs

How to use if-then in SQL Server? ›

The basic syntax of the SQL Server IF statement is simple: IF condition BEGIN -- code block to execute if the condition is true END; In the syntax above, the condition is an expression that evaluates to either true or false.

The Transact-SQL statement that follows an IF keyword and its condition is executed if the condition is satisfied: the Boolean expression returns TRUE . The optional ELSE keyword introduces another Transact-SQL statement that is executed when the IF condition isn't satisfied: the Boolean expression returns FALSE .

The syntax for using the SQL EXISTS operator is as follows: SELECT columns FROM table1 WHERE EXISTS (subquery); columns : The columns you want to retrieve from table1 . table1 : The name of the table you're querying.

The condition statement follows the 'SELECT' and 'FROM' keywords in your query. For example, if you want to select all records from a table named 'employees' where the salary is greater than 50000, you would write: `SELECT * FROM employees WHERE salary > 50000;`.

A conditional statement (also called an if-then statement) is a statement with a hypothesis followed by a conclusion. The hypothesis is the first, or “if,” part of a conditional statement. The conclusion is the second, or “then,” part of a conditional statement. The conclusion is the result of a hypothesis.

The if / then statement is a conditional statement that executes its sub-statement, which follows the then keyword, only if the provided condition evaluates to true: if x < 10 then x := x+1; In the above example, the condition is x < 10 , and the statement to execute is x := x+1 .

The if-else statement is used to execute both the true part and the false part of a given condition. If the condition is true, the if block code is executed and if the condition is false, the else block code is executed.

You can have multiple conditions in your if statement by combining it with any logical operator like and or not . For example: age = input() if(age >= 18 && age > 0 ||age <= 40 ){ print("Allowed") In this example there are total 3 conditions given in the if statement.

The SQL IF statement is often complemented by the ELSE statement. You can use the ELSE block if you want to execute an SQL script where the IF statement returns false. As with the IF statement, you can execute multiple statements inside an ELSE block, you simply enclose them inside BEGIN and END statements.

How to check if exists in SQL Server? ›

To define if the database in question exists in SQL Server, we can use the standard T-SQL means, querying the DB_ID() function or the sys. databases catalog view. Which one to choose depends on your preferences.

The SQL EXISTS keyword is used to check if at least one value is found in a subquery. It doesn't work with a literal list of values like the IN keyword does.

While CASE statements are the appropriate solution for returning rows of data, there is an actual IF ELSE statement in SQL Server too. You can use it for stored procedures or working with logic outside of rows.

To use two WHERE conditions in SQL, you utilise the AND or OR operators. The AND operator is used when both conditions must be true, while the OR operator is used when either condition can be true.

You can use IF-THEN statements to check for errors when inputting data into the spreadsheet.

SQL While loop syntax

END; The while loop in SQL begins with the WHILE keyword followed by the condition which returns a Boolean value i.e. True or False. The body of the while loop keeps executing unless the condition returns false. The body of a while loop in SQL starts with a BEGIN block and ends with an END block.

The final argument to IIF is returned in the event of an UNKNOWN result for the comparison. If this argument is left out, Null is returned. The IF THEN ELSE function evaluates a sequence of test conditions and returns the value for the first condition that is true. If no condition is true, the ELSE value is returned.