Relational Databases

• Using information schema

        SELECT 
            table_schema, 
            table_name
        FROM 
            information_schema.tables;
  

• Taking the look at the columns of a certain table using information scehma

        SELECT
            table_name, 
            column_name,
            data_type
        FROM
            information_schema.tables
        WHERE
            table_name = 'pg_config';
  

• Creating new tables with CREATE TABLE

  Syntax:

        CREATE TABLE table_name (
            column_a data_type,
            column_b data_type,
            column_c data_type
        );
  

  • Example:

      CREATE TABLE weather (
          clouds text, 
          temperature numeric,
          weather_station char(5)
      )
    

• INSERT INTO statemnt

        INSERT INTO table_name (column_a, column_b)
        VALUES ("value_a", "value_b");
  

• RENAME a column

        ALTER TABLE table_name
        RENAME COLUMN old_name TO new_name;
  

• DROP a column

        ALTER TABLE table_name
        DROP COLUMN column_name;