ODBC Server Reference Manual

Using Pass-Through Mode

HP NonStop ODBC Server Reference Manual—429151-002

6-20

Locking Data

The following examples show how to use pass-through mode to lock data.

Locking or Unlocking a Table

You can obtain an exclusive lock by using the LOCK statement in pass-through mode:

select "tdm: sql lock table $vol3.prsntabs.employee

in exclusive mode"

update $vol3_pertabs..employee

set salary = salary * 1.15

where deptnum = 2500

select "tdm: sql unlock table $vol3.prsntabs.employee"

You do not need to update the mapping tables after locking or unlocking a table. The

preceding UPDATE statement is not executed using pass-through mode.

Using PREPARE, EXECUTE, and RELEASE Statements

The following examples show how to use the PREPARE, EXECUTE, and RELEASE

statements.

The following statement prepares an INSERT statement and saves it as EMPIN:

select "tdm: sql prepare empin

from insert into $vol3.prsntabs.employee

values (?, ?, ?, ?, ?, ?)"

The following statement executes the prepared statement, specifying a value for each

column (EMPNUM, FIRST_NAME, LAST_NAME, DEPTNUM, JOBCODE, SALARY) of

the EMPLOYEE table:

select "tdm: sql execute empin

using 606, 'Amy', 'Ryan', 3100, 300, 55000"

The following statement releases the prepared statement:

select "tdm: sql release empin"

Managing Traces

The following example statement sets several trace options:

select "tdm: set tra_name trace01 tra_log_tablename

data_disk01_persnl..logtab1 log_to_hometerm y tra_error y"

The following example statement starts a server trace:

select "tdm: set tra_mode_on y"

The following example statement stops a server trace:

select "tdm: set tra_mode_on n"