SQL Syntax

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You enter your SQL statements into WordPerfect by typing them into the SQL Statement box in the Input Data dialog.

SQL is a standard language for defining and manipuating relationally-stored data. It has two distinct functions: data definition, and data manipulation. Data definition deals with the structure of the data, e.g. which tables, indices, etc. exist, together with the relationships between the tables. Data manipulation deals with the contents of the data tables, i.e. values stored in each of the data rows.

International standards define the SQL language, thus providing a common interface between data servers and the client applications. Some software houses have their own dialects of this language. However, standard SQL2 is recognized by nearly all ODBC drivers.

Data Definition

Statement	Description
CREATE TABLE	Defines the structure of a data table, including its indexes.
ALTER TABLE	Redefines the structure of a data table, including its indexes.
CREATE INDEX	Creates an index on a specific data table.
DROP	Deletes a table, index or constraint.

Data Manipulation

Statement	Description
SELECT	Retrieves data rows from one or more existing tables.
INSERT INTO	Appends new rows to an existing table.
UPDATE	Updates rows of an existing table.
DELETE	Deletes rows from an existing table
UNION	Merges two results tables into a single table

Data Types

The most common general data types, together with some specific to Microsoft Access, are listed below:

The following data types are defined by ANSI:

Data Type	Description	Synonyms
CHAR(Length)	String data type where Length=max number of characters	CHARACTER, TEXT
BOOLEAN	True or False	LOGICAL
DATE	Any valid date
TIME	Any valid time	TIMESTAMP
REAL	Singe-precision floating point number
FLOAT	Double-precision floating point number
SMALLINT	Short integer (2 bytes)
INTEGER	Long integer (4 bytes)

Microsoft Access defines the following additional data types:

Data Type	Description	Synonyms
BYTE	1 byte of data
COUNTER	An automatically incrementing long integer-compatible data type used primarily as a key	AUTOINCREMENT, AUTONUMBER
CURRENCY	Special data type for financial purposes	MONEY
LONGTEXT	Textual data which may be over 255 characters in length	NOTE, MEMO

NOTE: Date and time formats differ between DBMSs. For example, Access requires dates delimited with hash marks, e.g. '#20/04/1996#'