In this section, we cover common string functions seen in SQL. Different RDBMS may employ different string functions, and there may also be differences in the syntax for each RDBMS even when the function call is the same. All such differences are explained in each section. Please note that we do not list all possible SQL string functions in this tutorial. Rather, the most commonly used ones are covered.
| SQL String Function | Description |
|---|
| CAST | Converts data from one data type to another. |
| CONVERT | Converts data from one data type to another. |
| CONCATENATE | Combines the results of several columns together. |
| SUBSTRING | Returns a portion of a string. |
| INSTR | Finds the starting location of a pattern in a string. |
| TRIM | Removes specified prefix or suffix from a string. The most common pattern being removed is white space. |
| LENGTH | Returns the length of a string. |
| REPLACE | Updates the content of a string. |
| TO_DATE | Converts a string to a date. |