VALUES( 'Y', 'This is a test for varchar', 'This is a very long text for the PostgreSQL text column' ) Code language: SQL (Structured Query Language) ( sql ) Let’s fix it: INSERT INTO character_tests (x, y, z) This is because the data type of the x column is char(1) and we tried to insert a string with three characters into this column. PostgreSQL issued an error: ERROR: value too long for type character(1) Code language: SQL (Structured Query Language) ( sql ) VALUES( 'Yes', 'This is a test for varchar', 'This is a very long text for the PostgreSQL text column') Code language: SQL (Structured Query Language) ( sql ) Then, insert a new row into the character_tests table. ) Code language: SQL (Structured Query Language) ( sql ) Let’s take a look at an example to see how the CHAR, VARCHAR, and TEXT datatypes work.įirst, create a new table called character_tests: CREATE TABLE character_tests ( And you use the VARCHAR(n) when you want PostgreSQL to check for the length. In most cases, you should use TEXTor VARCHAR. Unlike VARCHAR, The CHARACTER or CHAR without the length specifier ( n) is the same as the CHARACTER(1) or CHAR(1).ĭifferent from other database systems, in PostgreSQL, there is no performance difference among the three character types. The advantage of specifying the length specifier for the VARCHAR data type is that PostgreSQL will issue an error if you attempt to insert a string that has more than n characters into the VARCHAR(n) column. The performance of the VARCHAR (without the size n) and TEXT are the same. If you do not specify the n integer for the VARCHAR data type, it behaves like the TEXT datatype. The TEXT data type can store a string with unlimited length. If a string explicitly casts to a CHAR(n) or VARCHAR(n), PostgreSQL will truncate the string to n characters before inserting it into the table. However, one exception is that if the excessive characters are all spaces, PostgreSQL truncates the spaces to the maximum length ( n) and stores the characters. If you try to store a string that has more than n characters, PostgreSQL will issue an error. The following table illustrates the character types in PostgreSQL: Character Typesīoth CHAR(n) and VARCHAR(n)can store up to n characters. PostgreSQL provides three primary character types: CHARACTER(n) or CHAR(n), CHARACTER VARYING(n) or VARCHAR(n), and TEXT, where n is a positive integer. Introduction to the PostgreSQL character types Summary: in this tutorial, you will learn about the PostgreSQL character data types including CHAR, VARCHAR, and TEXT, and learn how to select the right character types for your tables.
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