MultiBase
CTSQL. Database Access Language
CTSQL. Database Access Language
CTLSQL is the database access language provided by MultiBase.
Constituted as a “superset” of the standard SQL language defined by the ANSI X3H2 committee, to which additional functionality has been added to fill in the deficiencies of said definition, as well as extended features of the SQL2 and SQL3 definitions of the same committee.
Due to its functionality we can point out the existence of the following sub languages within the CTSQL structure.
Oriented to the definition and maintenance of the database structure.
Oriented to the insertion, deletion and maintenance of data from the database.
Oriented to the control of access permissions, concurrency control and transactions on the database.
Set of instructions dedicated to the extraction of information from the database.
CTSQL provides various integrity mechanisms grouped into two distinct classes: Referential Integrity and Dictionary Integrity.
These mechanisms achieve two fundamental objectives, on the one hand, reducing the code to be written in the programs and, on the other, increasing the security of the applications built.
The implementation of bidirectional cursors in CTSQL allows scrolling up and down in query windows (based on the database) built using the CTL WINDOW statement.
For each database, CTSQL allows the definition of a table that specifies the ordering sequence.
Depending on the character set used, it indicates the position in which those characters that, otherwise, would not be correctly ordered in the standard ASCII sequence (eñes, accented vowels, etc.) should be placed.
The CTSQL implementation includes the possibility of using a VIEW to modify the base tables from which it is derived. This means that any of these operations will be decomposed into the corresponding ones on the base tables.
A JOIN operation defines the link between tables through one or more columns whose values satisfy a link condition.
CTSQL has a transaction handling mechanism through which complex database update operations can be treated individually, ensuring that either all the operations are carried out, or none are carried out.
Also, CTSQL incorporates a mechanism for recovering the state of a database after a system crash.