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It has the following salient features and strong processing capabilities:
It can retrieve data from a database through Query processing.
It can insert records in a database.
It can update records in a database.
It can create new databases and modify the existing ones.
It can create new tables in a database.
It can create views in a database.
It allows modifying the security settings of the system.
CTM: SQL (Structured Query Language) is a unified, non-procedural language used for creating, accessing,
handling and managing data in relational databases.
12.9 ADVANTAGES OF SQL
SQL has the following advantages:
1. Ease of use: It is very easy to learn and use and does not require high-end professional training
to work upon it.
2. Large volume of databases can be handled quite easily.
3. No coding required: It is non-procedural and a unified language, i.e., we need not specify the
procedures to accomplish a task but only need to give a command to perform the activity.
4. SQL can be linked to most of the other high-level languages which makes it the first choice for
database programmers.
5. Portable: It is compatible with other database programs like Dbase IV, FoxPro, MS Access, DB2,
MS SQL Server, Oracle, Sybase, etc.
6. SQL is not a case-sensitive language, i.e., both capital and small letters are recognized.
12.10 CLASSIFICATION OF SQL STATEMENTS
SQL is the language used to interact with the database. The SQL statements or commands that we
type are the statements that are regarded as the instructions to the database.
SQL provides different types of statements or commands for different purposes. These statements
are classified into the following categories:
SQL statements
Relational Database and SQL
Data Definition Data Manipulation Data Control Transaction Control
Language (DDL) Language (DML) Language (DCL) Language (TCL)
Fig. 12.14: Classification of SQL statements
DCL and TCL are beyond the scope of this book. So, we shall be discussing only DDL and DML
commands in detail.
12.13
