EXPLAIN command displays the execution plan for a statement. When we execute a statement using EXPLAIN ANALYZE command, the query plan will include the actual row scan count for each table.

Syntax

Following is the generic syntax of the EXPLAIN command.

EXPLAIN { [ PLAN FOR ] | ANALYZE } { select | insert | update | delete | merge}

Along with this syntax we can use select, insert, delete, and merge.

Example

This example explains the query plan details of the customer with ID 1.

EXPLAIN SELECT * FROM CUSTOMER WHERE ID = 1;

The above command produces the following output −

The SQL INSERT statement is used to add new rows of data to a table in the database.

Syntax

Following is the basic syntax of INSERT INTO statement.

INSERT INTO tableName
{ [ ( columnName [,...] ) ]
{ VALUES
{ ( { DEFAULT | expression } [,...] ) } [,...] | [ DIRECT ] [ SORTED ] select } } |
{ SET { columnName = { DEFAULT | expression } } [,...] }

Using this INSERT statement, we can insert a new record or new rows into a table. When using DIRECT clause, the results are directly affected to the target table without any intermediate step. However, while adding values for all the columns of the table, make sure the order of the values is in the same order as the columns in the table.

Example

Let us take an example and try to insert the following given records into the Customer table.

We can get all the given records into the customer table by executing the following commands.

INSERT INTO CUSTOMER VALUES (1, ''Ramesh'', 32, ''Ahmedabad'', 2000);
INSERT INTO CUSTOMER VALUES (2, ''Khilan'', 25, ''Delhi'', 1500);
INSERT INTO CUSTOMER VALUES (3, ''kaushik'', 23, ''Kota'', 2000);
INSERT INTO CUSTOMER VALUES (4, ''Chaitali'', 25, ''Mumbai'', 6500);
INSERT INTO CUSTOMER VALUES (5, ''Hardik'', 27, ''Bhopal'', 8500);
INSERT INTO CUSTOMER VALUES (6, ''Komal'', 22, ''MP'', 4500);
INSERT INTO CUSTOMER VALUES (7, ''Muffy'', 24, ''Indore'', 10000);

CALL is a SQL command which belongs to H2 database server. This command is used to calculate a simple expression. It returns the result of the given expression in a single column field. When it returns an array of results, then each element in the array is displayed as a column value.

Syntax

Following is the generic syntax of the CALL command.

CALL expression;

We can use the arithmetic expression in this syntax.

Example

Let us take an example and execute an arithmetic expression (15 * 25) using call command.

CALL 15*25;

The above command produces the following output.

BACKUP is the command used to take database backup into a separate .zip file. Objects are not locked, and when it takes backup the transaction log is also copied. Admin rights are required to execute this command.

Syntax

Following is the generic syntax of the Backup command.

BACKUP TO fileNameString;

Example

In this example, let us take a backup of the current database into backup.zip file. Use the following command for the same.

BACKUP TO ''backup.zip

On executing the above command, you will get the backup.zip file in your local file system.