![]() Foreign key constraints in PostgreSQL state that values in the first column must appear or present with values in the second column.PostgreSQL foreign key maintains the referential integrity concepts with the two related tables.The foreign key states that the value in the column must match those in another row from another table. ![]() A foreign key is a type of constraint.A foreign key is most important in PostgreSQL.References: References are defined as creating a primary key on the first table and referencing that primary key on the second table to implement it.If the column row contains a numeric value, we define the integer data type for the same. We define the data type of a specific column and what kind of data we have inserted into a table. Data type: We need to define the data type of the column.Primary key: We are creating a primary key on the first table column and giving reference to that primary key on the second table column to implement a foreign key in PostgreSQL.Column_name1 to column_nameN: Column name of the table on which we are implementing the foreign key and primary key in PostgreSQL.Table name: Name of the table on which column we have implementing the foreign key in PostgreSQL.Create a table statement to create a new table and implement the column’s primary and foreign keys.
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