Find all string (character) columns in PostgreSQL database

String in PostgreSQL are columns with the following data types: character varying, character, binary, text, "char", name.

The query below lists all columns with string data types.

Query

select col.table_schema,
       col.table_name,
       col.ordinal_position as column_id,
       col.column_name,
       col.data_type,
       col.character_maximum_length as maximum_length
from information_schema.columns col
join information_schema.tables tab on tab.table_schema = col.table_schema
                                   and tab.table_name = col.table_name
                                   and tab.table_type = 'BASE TABLE'
 where col.data_type in ('character varying', 'character',
                         'text', '"char"', 'name')
      and col.table_schema not in ('information_schema', 'pg_catalog')
order by col.table_schema,
         col.table_name,
         col.ordinal_position;

Columns

  • table_schema - name of the schema
  • table_name - name of the table
  • column_id - column position in table
  • column_name - name of the column
  • data_type - type of data
  • maximum_length - maximum length in characters

Rows

  • One row represents one column with a string data type
  • Scope of rows: all columns containing string data types in the schema
  • Ordered by schema name, table name and position in table

Sample results