#POSTGRESQL DELETE TABLE SOFTWARE#

This will display the message that the command is executed, and the execution time is also shown here. Instead of writing the whole query, you can simply go to the scripts option and select the вЂњdelete scriptвЂќ this will automatically display the delete query. The output portion of the page shows the resultant. Show the data of the dummy table вЂsampleвЂ™ through the select command. After providing the password, navigate to the left navigation bar, select the database name, and go to the вЂquery toolвЂ™. We can also apply the same queries to the pgAdmin. The dashboard of postgresql is вЂpgAdminвЂ™. Let us see the working.ДЄnother way of removing the table is to use the word вЂњdropвЂќ with the table name. Consider the table as described previously, вЂњsystemвЂќ. We only use a вЂњReturningвЂќ keyword and вЂњ*вЂќ at the end of the command. So to preview the specific row, there is an easy method. Whenever we delete any data from the table, only the number of rows that are deleted are displayed but not the row itself. This means that the вЂsystemвЂ™ table is used only for reference. You can see that the rows from the вЂsoftwareвЂ™ table are removed, whereas the вЂsystemвЂ™ table is intact.

If we want to check the data left in both tables, checked through a select statement. When we execute the command, it shows that 2 records are deleted. So the system will match the name with the one present in the вЂsystemвЂ™ table. Now there is another constraint, constraint of the name.

#POSTGRESQL DELETE TABLE SOFTWARE#

Now navigate back to the tables, and you will find out that in software and system tables, two rows have the same id. This query asks the system to fetch one record where both IDS of tables are the same with a common name. Whereas after the вЂexistsвЂ™ portion, it is for the table software. The first position of the command is for the вЂњsoftwareвЂќ table that is to delete a row from the software. > DELETE FROM software where exists ( select 1 from system where system.id = software.id AND system.name = software.name ) Now we will apply the delete command on the table software because a row will be deleted from the table вЂsoftwareвЂ™ concerning the table вЂsystemвЂ™. The data of both tables is displayed through the select statement.

Whereas the other one is вЂњsystemвЂќ that contains the id and names of the system. One is a вЂњsoftwareвЂќ having information about software. This example deals with the usage of two tables in deleting the record. You will come to know that the вЂњFROMвЂќ clause is not sufficient for this purpose. Sometimes you encounter such situations when you need to delete the record in one table depending on the other table. This statement makes the delete command more complex. You will see the involvement of the вЂњEXISTSвЂќ statement. If not! Then this example will escalate your concept regarding the usage of two tables together in a single query. You must be familiar with the relation between the two tables. delete from sample1 where id = 6 AND age = 23 ДЇrom the result, you can notice that one row is deleted, and the rest are displayed by using the select statement.

Postgresql delete table