> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/reference/sql-functions/control-flow-functions/if-function.md).

# IF Function

Complete IF() function reference: IF(expr1,expr2,expr3) conditional syntax, TRUE/NULL evaluation rules, return type context (numeric/string), and examples.

## Syntax

```bnf
IF(expr1,expr2,expr3)
```

## Description

If `expr1` is `TRUE` (`expr1 <> 0` and `expr1 <> NULL`) then `IF()` returns `expr2`; otherwise it returns `expr3`. `IF()` returns a numeric or string value, depending on the context in which it is used.

`expr1` is evaluated as a number. A string that doesn't start with a number evaluates to `0`, so it counts as false, and a string with trailing non-numeric characters is truncated to its leading number. Both produce warning 1292.

**Note:** There is also an [IF statement](/docs/server/reference/sql-statements/programmatic-compound-statements/if.md) which differs from the`IF()` function described here.

## Examples

```sql
SELECT IF(1>2,2,3);
+-------------+
| IF(1>2,2,3) |
+-------------+
|           3 |
+-------------+
```

```sql
SELECT IF(1<2,'yes','no');
+--------------------+
| IF(1<2,'yes','no') |
+--------------------+
| yes                |
+--------------------+
```

```sql
SELECT IF(STRCMP('test','test1'),'no','yes');
+---------------------------------------+
| IF(STRCMP('test','test1'),'no','yes') |
+---------------------------------------+
| no                                    |
+---------------------------------------+
```

A string condition is converted to a number:

```sql
SELECT IF('abc',1,2), IF('1abc',1,2);
+---------------+----------------+
| IF('abc',1,2) | IF('1abc',1,2) |
+---------------+----------------+
|             2 |              1 |
+---------------+----------------+
1 row in set, 2 warnings (0.00 sec)

Warning (Code 1292): Truncated incorrect DOUBLE value: 'abc'
Warning (Code 1292): Truncated incorrect DOUBLE value: '1abc'
```

## See Also

There is also an [IF statement](/docs/server/reference/sql-statements/programmatic-compound-statements/if.md), which differs from the `IF()` function described above.

<sub>*This page is licensed: GPLv2, originally from*</sub> [<sub>*fill\_help\_tables.sql*</sub>](https://github.com/MariaDB/server/blob/main/scripts/fill_help_tables.sql)

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