PostgreSQL Left Join

All the matched and unmatched records are retrieved from the table present on the left hand side of the join operator.Left Join is used to return all data or records from the Table 1 plus match records to tables 2. If there is no match, the result from the right will be NULL. This is also known as LEFT (OUTER) JOIN.

Left Joins Syntax :

The syntax of the Left Joins statement is −

SELECT col_name,...
FROM table_name1 t1  [LEFT] JOIN table_name2 t2
ON t1.col_name = t2.col_name

PostgreSQL Left Join Example :

Consider the Customer table with the following records -

Consider the Order table with the following records -

TEST CASE 1 :-Let us join these two tables using the Left JOIN as follows

SELECT  ID, Name, Amount, Date
FROM Customer
LEFT JOIN Order
ON Customer.ID = Order.CustomerID;

The result for the respective PostgreSQL query is as follows −

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