Oracle® Database Gateway for IMS User's Guide 11g Release 1 (11.1) B31053-01 |
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This appendix contains the following sections:
See Also: Oracle Database SQL Reference for detailed descriptions of keywords, parameters, and options and the IMS documentation for details of executing SQL statements in a transaction. |
With a few exceptions, the gateway provides full support for Oracle DELETE
, INSERT
, SELECT
, and UPDATE
statements.
The gateway does not support Oracle data definition language (DDL) statements. No form of the Oracle ALTER
, CREATE
, DROP
, GRANT
, or TRUNCATE
statements can be used. Instead, for ALTER
, CREATE
, DROP
, and GRANT
statements, use the pass-through feature of the gateway if you need to use DDL statements against the IMS database.
Note: TRUNCATE cannot be used in a pass-through statement. |
The DELETE
statement is fully supported. However, only Oracle functions supported by IMS can be used.
The INSERT
statement is fully supported. However, only Oracle functions supported by IMS can be used.
The SELECT
statement is fully supported, with these exceptions:
CONNECT BY condition
NOWAIT
START WITH condition
WHERE CURRENT OF
All functions are evaluated by the IMS database after the gateway has converted them to IMS SQL.
Oracle SQL functions with no equivalent function in IMS are not supported in DELETE
, INSERT
, or UPDATE
statements, but are evaluated by the Oracle database server if the statement is a SELECT
statement. That is, the Oracle database server performs post-processing of SELECT
statements sent to the gateway.
If an unsupported function is used in a DELETE
, INSERT
, or UPDATE
, statement, the following Oracle error occurs:
ORA-02070: database db_link_name does not support function in this context
The gateway translates the following Oracle database server functions in SQL statements to their equivalent IMS functions:
The following table specifies the arithmetic operators.
Oracle | IMS |
---|---|
+ |
+ |
- | - |
* |
* |
/ |
/ |
The following table specifies the comparison operators.
Oracle | IMS |
---|---|
= |
= |
> | > |
< |
< |
>= | >= |
<= |
<= |
<>, !=, ^= | <>, != |
IS NOT NULL | IS NOT NULL |
IS NULL | IS NULL |
The following table specifies the group functions.
Oracle | IMS |
---|---|
AVG | AVG |
COUNT | COUNT |
MAX | MAX |
MIN | MIN |
SUM | SUM |
The following table specifies the string functions.
Oracle | IMS |
---|---|
|| |
+ (expression1 + expression2) |
ASCII | ASCII |
CHR | CHAR |
INSTR | CHARINDEX |
LENGTH | CHAR_LENGTH |
LOWER | LOWER |
SUBSTR (second argument cannot be a negative number) | SUBSTRING |
UPPER | UPPER |
The following table specifies other functions.
Oracle | IMS |
---|---|
ABS | ABS |
CEIL | CEILING |
COS | COS |
EXP | EXP |
FLOOR | FLOOR |
LN | LOG |
LOG | LOG10 |
MOD | % |
NVL | IS NULL |
POWER | POWER |
ROUND | ROUND |
SIN | SIN |
SQRT | SQRT |
TAN | TAN |