SQL ... END SQL

Performs an SQL that is not part of the static SQL syntax.

Syntax

SQL
 sql-statement
END SQL

where sql-statement is:

  sql-keyword
| identifier
| INTO $host-variable [,...]
| $host-variable
| {+ sql-directive }
| --+ sql-directive
| --# fgl-comment
[...]

sql-keyword is any keyword of the SQL language.
identifier is a regular SQL identifier such as a table or column name.
host-variable is a program variable defined in the current scope.
sql-directive is a special comment to be kept in the SQL statement.
fgl-comment defines a comment that will be interpreted as a regular syntax element.

Usage

SQL blocks provide a convenient way to execute specific SQL statements that are not supported in the language as static SQL statements.

SQL blocks start with the SQL keyword and end with the END SQL keywords. The content of the SQL block is parsed by the fglcomp compiler to extract host variables, but the SQL statement syntax is not checked. This is actually the main purpose of SQL blocks, compared to regular static SQL statements; with SQL blocks, you can use any recent SQL statement introduced by the latest version of your database server. Note however, that you can achieve the same result using dynamic SQL instructions.

Only one SQL statement can be included in an SQL block. Using the ; semicolon statement separator is forbidden.

Program variables can be used inside the SQL statement. However, unlike static SQL statements, each host variable must be identified with a $ dollar prefix. The list of fetch targets must be preceded by the INTO keyword, as in static SELECT statements. Complete records can be used in SQL blocks by using the dot star notation ($record.*), you can also use the THROUGH or THRU keywords), as well as array elements.

SQL blocks can also be used to declare a cursor with the DECLARE mycursor CURSOR FOR SQL ... END SQL syntax.

SQL directives can be used inside SQL blocks as special comments with the {+} or --+ syntax. The SQL directives will be kept in the SQL text that will be executed by the database server. You typically write optimizer hints with the SQL directives syntax.

The --# specific comment is supported for backward compatibility. The SQL text following this marker will be parsed as regular SQL text, but will be ignored by other compilers. It is not recommended to use this feature.

You can check the resulting SQL statement after parsing by using the -S option of fglcomp.

Example

MAIN
   DEFINE myrec RECORD
            key INTEGER,
            name CHAR(10)
         END RECORD
   DATABASE stock 
   LET myrec.key = 123
   SQL
     SELECT (+EXPLAIN) items.* INTO $myrec.*
        FROM items WHERE key=$myrec.key 
   END SQL
END MAIN