CONTINUE

In SQL Server, control-of-flow statements allow developers to manage the execution sequence of Transact-SQL (T-SQL) code. One such control statement is the CONTINUE statement, which is used inside looping constructs to skip the remaining statements in the current iteration and immediately move to the next iteration of the loop.

The CONTINUE statement is especially useful when certain conditions occur during loop execution and you want to bypass the rest of the logic for that iteration without terminating the loop entirely.

What Is the CONTINUE Statement?

The CONTINUE statement instructs SQL Server to stop executing the remaining statements in the current loop iteration and begin the next iteration of the loop.

Key characteristics:

Can only be used inside a loop.
Skips the remaining statements in the current iteration.
Does not exit the loop (unlike BREAK).

Supported loop types: WHILE loops.

Syntax

CONTINUE;

The syntax is simple and does not accept any parameters. Its behavior depends entirely on where it is placed within the loop.

Basic Example

Consider a loop that processes numbers from 1 to 5 but skips the number 3:

DECLARE @Counter INT = 1;

WHILE @Counter <= 5
BEGIN
    IF @Counter = 3
    BEGIN
        SET @Counter = @Counter + 1;
        CONTINUE;
    END


    PRINT 'Counter value: ' + CAST(@Counter AS VARCHAR);
    SET @Counter = @Counter + 1;
END

Output:

Counter value: 1
Counter value: 2
Counter value: 4
Counter value: 5

In this example, when @Counter equals 3, the CONTINUE statement skips the PRINT statement and immediately proceeds to the next iteration.

CONTINUE vs BREAK

It is common to confuse CONTINUE with BREAK. While both control loop flow, they behave very differently.

Statement	Behavior
CONTINUE	Skips the current iteration and continues with the next one
BREAK	Terminates the loop entirely

BREAK Example

IF @Counter = 3
    BREAK;

This would stop the loop completely when @Counter equals 3.

Practical Use Cases

1. Skipping Invalid Data

When processing rows in a loop, you may encounter invalid or incomplete data. CONTINUE allows you to skip those rows without interrupting the entire process.

IF @Amount IS NULL OR @Amount < 0
    CONTINUE;

2. Conditional Processing

You can apply CONTINUE when only certain values meet your processing criteria.

IF @Status <> 'ACTIVE'
    CONTINUE;

3. Improving Code Readability

Using CONTINUE can reduce nested IF statements, making your T-SQL code easier to read and maintain.

Practical Scenarios for Using CONTINUE

Data Validation: Skip processing rows that do not meet certain criteria within a loop.
Error Handling: Skip iterations that encounter non-critical errors without stopping the entire loop.
Selective Processing: Process only specific subsets of data while ignoring others dynamically.

Important Considerations

Always ensure loop variables are properly updated before using CONTINUE. Failing to do so can result in infinite loops.
Overuse of loops in SQL Server can lead to performance issues. Whenever possible, consider set-based operations as an alternative.
CONTINUE cannot be used outside a WHILE loop.

Best Practices

Use CONTINUE sparingly and only when it improves clarity.
Prefer set-based logic over row-by-row processing.
Clearly comment why an iteration is being skipped.

Conclusion

The SQL Server CONTINUE statement is a simple yet powerful control-of-flow tool that helps manage loop execution efficiently. By allowing developers to skip specific iterations without terminating loops, it supports cleaner logic and better handling of conditional scenarios. When used correctly and judiciously, CONTINUE can make T-SQL scripts more readable and maintainable.

Understanding when and how to use CONTINUE along with related statements like BREAK is an important step toward writing robust SQL Server code.