isCOBOL Evolve : Language Reference : Embedded SQL Statements : SET
SET
The SET statement allows you to set specific database dependent settings host variables.
Format 1
EXEC SQL [ AT Database ]
 
  SET Options 
 
END-EXEC
Format 2
EXEC SQL [ AT Database ]
 
  SET Host-Variable = Expression
 
END-EXEC
Syntax rules
1. No syntax check is performed on the content of Options.
2. Host-Variable is a host variable.
3. Expression specifies a value and can take a number of different forms. It can be a constant value, a special register, an arithmetic calculation, a function, etcetera...
General rules
1. Database identifies the active connection that will execute the query and must be previously defined using a Format 4 DECLARE statement. By default, when the AT clause is used, the active connection is switched to the connection identified by Database and all the next statements will work on that connection; under the -csora option, instead, the connection is switched only for the current statement.
Format 1
2. The SET statement is passed as is to the underlying JDBC driver. If the driver doesn’t understand it, an SQL error will be generated.
Format 2
3. A Format 2 SET statement is automatically transformed to a SELECT query to retrieve the result of the function. The resulting query depends on the compatibility activated through compiler options.
When using the -csdb2 option, the query is:
select Expression into :Host-Variable from sysibm.sysdumm1
When using the -csora option, the query is:
select Expression into :Host-Variable from dual
If none of the above options is used, the query is:
select Expression into :Host-Variable
 
Examples
Set the current transaction as READ ONLY and give it a name. This syntax is supported by the Oracle database
   exec sql
     set transaction read only name 'mytran'
   end-exec
Retrieve the current schema through the appropriate special register. This syntax is supported by the DB2 database and requires the -csdb2 compiler option
   exec sql
     set :wrk-schema = current schema
   end-exec