“tab_1”, “tab_2”, and “tab3” represents the tables to be joined. Use the below syntax to combine multiple tables using “INNER JOIN”: SELECT, , Postgres uses the INNER JOIN to get matching results from two or more tables based on the defined join conditions. This post will explain how to use the Postgres INNER JOIN to merge three different tables. PostgreSQL supports various types of JOINS, such as “INNER JOIN”, “OUTER JOIN”, “NATURAL JOIN”, “SELF JOIN”, etc. To do that, the Joins can be used in databases. To get the related information from different tables, you might need to merge various tables. In relational databases, different tables are linked with each other using various constraints. This article has explained how to use the INNER JOIN to combine three different tables in PostgreSQL.PostgreSQL is a famous relational database that is freely available for all operating systems like Windows, Linux, and MacOS. To avoid ambiguity, the tables’ columns must be specified with the table name. The “ON” clause is utilized with the INNER JOIN to define a joining condition. The output demonstrates that the given three tables have been joined successfully. The second INNER JOIN is utilized to combine the emp_info table with the other two tables based on the “dpt_id” column: The first INNER JOIN is utilized to merge the “emp_bio” and “emp_details” tables based on the “e_id” column. The SELECT statement specifies the columns to be fetched from all three tables. Now use the INNER JOIN to combine the three given tables: SELECT emp_bio.e_name, emp_bio.emp_name, In the “emp_details” table, the “e_id” and “dpt_id” are foreign keys. The final table is “emp_details” which contains the following records: SELECT * FROM emp_details The “dpt_id” column is defined as a primary key in the “dpt_info” table. Now, run the “SELECT” command to fetch the results from the “dpt_info” table: SELECT * FROM dpt_info The “e_id” column is defined as a primary key in the “emp_bio” table. Let’s type the “SELECT *” command to fetch all the tables: SELECT * FROM emp_bio All three tables are connected via the foreign key constraint. Suppose we have already created three sample tables named “emp_bio”, “dpt_info”, and “emp_details''. The “ON” clause specifies the joining condition.Įxample: Joining Three Tables in Postgres The “INNER JOIN” joins the given tables on the basis of the defined JOIN condition. To avoid ambiguity, the tables’ columns must be specified with the table name, such as “tab_1.col_name”, “tab_2.col_name”, and tab_3.col_name. PostgreSQL is a famous relational database that is freely available for all operating systems like Windows, Linux, and MacOS.
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