PostgreSQL TRANSLATE() Function

The PostgreSQL TRANSLATE() function performs several single-character, one-to-one translations in one operation.

Syntax

The following illustrates the syntax of the PostgreSQL TRANSLATE() function:

TRANSLATE(string, from, to)

Arguments

The PostgreSQL TRANSLATE() function accepts three arguments:

1) string
is a string subjected to translation.

2) from
is a set of characters in the first argument (string) that should be replaced.

3) to
is a set of characters that replaces the from in the string.

Notice that if from is longer than to, the TRANSLATE() function removes the occurrences of the extra characters in from.

Return value

The PostgreSQL TRANSLATE() function returns a string with the characters in the one set of characters replaced by another set of characters.

Examples

Let’s see some examples of using the TRANSLATE() function to understand how it works.

1) Basic TRANSLATE() function example

See the following statement:

SELECT TRANSLATE('12345', '134', 'ax')

In this example:

The character '1' in string '12345' is substituted by character 'a', The character '3' in the string '12345' is substituted by the character 'x'.
Because the string '134' has more characters than the string 'ax', the TRANSLATE() function removes the extra character in the string '134', which is '4', from the string '12345'.

The following illustrates the result:

translate
-----------
 a2x5
(1 row)

2) Single character replacement

The following example shows how to use the TRANSLATE() function to replace comma (,) with a semi-colon (;) in a comma-separated values list.

SELECT TRANSLATE('apple,orange,banana', ',', ';');

Here is the output:

translate
---------------------
 apple;orange;banana
(1 row)

3) Encrypting and decrypting a message

The following example shows how to use the TRANSLATE() function to encrypt a message:

SELECT TRANSLATE('a secret message',
                 'abcdefghijklmnopqrstuvxyz',
                 '0123456789acwrvyuiopkjhbq');

Here is the output:

translate
------------------
 0 o42i4p w4oo064
(1 row)

You can also decrypt the message '0 o42i4p w4oo064' using the function:

SELECT TRANSLATE('0 o42i4p w4oo064',
                     '0123456789acwrvyuiopkjhbq',
                     'abcdefghijklmnopqrstuvxyz');

Hence the output is:

translate
------------------
 a secret message
(1 row)

In this tutorial, you have learned how to use the PostgreSQL TRANSLATE() function to substitute characters in a set with another, one-to-one, in a single operation.