Naming Conventions

Previous  Top  Next

Absolute Database requires to apply the following rules and naming conventions to all SQL statements.

Database File Names

Absolute DB supports specifying a database file name in SQL statement. The main reason for specifying a database file name in a query is a selecting table records from multiple databases by a single query.
In all other cases you don't need to specify database file name within a SQL statement.
The database file name must be enclosed in double quotes (""):

SELECT * FROM "c:\data\parts_db.abs".parts, "c:\data\orders_db.abs".orders

Table Names

Absolute DB supports not only ANSI SQL identifiers, but it is advanced to support multi-word and national table names. A reserved word could also be used as a table name. In such specific cases the table name must be enclosed in single quotes, double quotes, or square brackets.

The following example illustrates using of standard identifier as a table name:

SELECT * FROM Employee

The next statement shows how to use multi-word table name:

SELECT * FROM "Our Employees"

Column Names

Absolute DB supports not only ANSI SQL identifiers, but it is advanced to support multi-word and national column names. A reserved word could also be used as a column name. In such specific cases the column name must be enclosed in square brackets:

SELECT [First Name] FROM Students

Correlation Names

To simplify SQL statement table and column correlation names are often used (AS keyword is optional):

SELECT E.EmpNo AS No FROM Employee E

Constants

Absolute DB supports string, number, boolean, currency, date, and time constants.
The string, date and time constants must be enclosed in single or double quotes.

To insert a single quote into a column, use two consecutive single quotation marks.
For example, to insert the characters "a'b" into col1, use:

INSERT INTO Orders (col1) VALUES('a''b')

Comments

Absolute Database supports single-line and multi-line comments which you can use to embed some remarks into SQL statement.

Single-line comment must contain '--' characters at the beginning of the comment line:

-- This query uses emp_db.abs database

SELECT * FROM Employee

Multi-line comment must be enclosed in /* and */ characters.
The following example uses multi-line comment to exclude temporarily some parts of the SQL statement.

SELECT * FROM Employee

/* WHERE EmpNo < 5

ORDER BY EmpNo */