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SQL programming
You can use the HCL Informix® implementation of the SQL language to develop applications for Informix database servers.
Guide to SQL: Syntax
The Informix® Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the Informix dialect of the SQL language.
SPL statements
These topics describe Stored Procedure Language (SPL) statements, which you use to write SPL routines. You can store these routines in the database as user-defined routines (UDRs).
SYSTEM
Executing the SYSTEM statement on Windows™
On Windows™ systems, any SYSTEM statements in an SPL routine are executed only if the current user who is executing the SPL routine has logged on with a password.

SQL programming
You can use the HCL Informix® implementation of the SQL language to develop applications for Informix database servers.
- Guide to SQL: Syntax
  The Informix® Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the Informix dialect of the SQL language.
  - Overview of SQL syntax
    These topics provide an overview about how to use the SQL statements, SPL statements, and syntax segments.
  - SQL statements
    This chapter describes the syntax and semantics of SQL statements that are recognized by Informix®.
  - SPL statements
    These topics describe Stored Procedure Language (SPL) statements, which you use to write SPL routines. You can store these routines in the database as user-defined routines (UDRs).
    - << Label >> statement
      Use the <<label>> statement of SPL to declare a statement label or a loop label.
    - CALL
    - CASE
      Use the CASE statement when program execution needs to take exactly one among multiple branches, depending on the value of an SPL variable or of a simple expression. The CASE statement is a logical alternative to the IF statement.
    - CONTINUE
    - DEFINE
    - EXIT
    - FOR
    - FOREACH
      Use the FOREACH statement to declare a direct cursor that can select and manipulate more than one row from a the result set of a query, or more than one element from a collection.
    - GOTO
    - IF
    - LET
    - LOOP
    - ON EXCEPTION
    - RAISE EXCEPTION
    - RETURN
    - SYSTEM
      - Executing the SYSTEM statement on UNIX™
        In SPL procedures for UNIX™ platforms, a specification that evaluates to a valid UNIX operating system command must immediately follow the SYSTEM keyword.
      - Executing the SYSTEM statement on Windows™
        On Windows™ systems, any SYSTEM statements in an SPL routine are executed only if the current user who is executing the SPL routine has logged on with a password.
      - Setting Environment Variables in SYSTEM Commands
    - TRACE
    - WHILE
      Use the WHILE statement to establish a loop with variable end conditions.
  - Data types and expressions
    These topics describe the data types and expressions that Informix®supports.
  - Other syntax segments
    These topics describe syntax segments, which are language elements, such as database object names or optimizer directives, that appear as a subdiagram reference in the syntax diagrams of some SQL or SPL statements.
  - Built-In Routines
  - Appendixes
- Guide to SQL: Reference
  The Informix® Guide to SQL: Reference contains the reference information for the system catalog tables, data types, and environment variables of the HCL Informix dialect of the SQL language, as implemented in HCL Informix. These topics also include information about the stores_demo, sales_demo, and superstore_demo databases that are included with HCL Informix.
- Guide to SQL: Tutorial
  The Informix® Guide to SQL: Tutorial shows how to use basic and advanced structured query language (SQL) to access and manipulate the data in your databases. It discusses the data manipulation language (DML) statements as well as triggers and stored procedure language (SPL) routines, which DML statements often use.

Executing the SYSTEM statement on Windows™

On Windows™ systems, any SYSTEM statements in an SPL routine are executed only if the current user who is executing the SPL routine has logged on with a password.

The database server must have the password and login name of the user in order to execute a command on behalf of that user.

The first SYSTEM statement in the following example of an SPL routine causes Windows™ to send an error message to a temporary file and to put the message in a system log that is sorted alphabetically. The second SYSTEM statement causes the operating system to delete the temporary file:

CREATE PROCEDURE test_proc()
   ...
   SYSTEM 'type errormess101 > %tmp%tmpfile.txt |
         sort >> %SystemRoot%systemlog.txt';
   SYSTEM 'del %tmp%tmpfile.txt'; 
   ...
END PROCEDURE; --test_proc

The expressions that follow the SYSTEM statements in this example contain variables %tmp% and %SystemRoot% that are defined by Windows™.