The Drop Clause

The Drop clause is used to remove a definition from the database. It is most commonly used to

remove a table from a database but can also be used for removing several other constructs. In

2.0 it can be used to remove the definition of an index, a sequence, or a table. It should be

noted that 

dropping

 a table or an index removes the data associated with that object as well as

the definition.

The syntax of the drop clause as well as examples of its use are given below.

DROP TABLE table_name

DROP INDEX index_name FROM table_name

DROP SEQUENCE FROM table_name

for example

DROP TABLE emp_details

DROP INDEX idx1 FROM emp_details

DROP SEQUENCE FROM emp_details

The Insert Clause

Unlike ANSI SQL, you cannot nest a select within an insert (i.e. you cannot insert the data

returned by a select). If you do not specify the field names they will be used in the order they

were defined   you must specify a value for every field if you do this.

INSERT INTO table_name [ ( column [ , column ]** ) ]

G   

VALUES (value [, value]** )

for example

INSERT INTO emp_details

G   

(first_name, last_name, dept, salary)

VALUES ( David ,  Hughes ,  Development , 12345 )

INSERT INTO emp_details

VALUES ( David ,  Hughes ,  Development , 12345 )

The number of values supplied must match the number of columns.

The Select Clause

The SELECT offered by mSQL lacks some of the features provided by the standard SQL

specification. Development of mSQL 2 is continuing and some of this missing functionality

will be made available in the next beta release. At this point in time, mSQL s select does not

provide

Nested selects

G   

Implicit functions (e.g. count(), avg() )

G   

It does however support:

Joins   including table aliases

G