8.7 Pro*C/C++ and Pro*COBOL API for LOBs
This section describes the mapping of Pro*C/C++ and Pro*COBOL locators to locator pointers to access a LOB value.
Embedded SQL statements enable you to access data stored in
BLOBs, CLOBs, and NCLOBs.
See Also:
Pro*C/C++ Programmer's Guide and Pro*COBOL Programmer's Guide for detailed documentation, including syntax, host variables, host variable types and example code.Unlike locators in PL/SQL, locators in Pro*C/C++ and Pro*COBOL are mapped to locator pointers which are then used to refer to the LOB value. To successfully complete an embedded SQL LOB statement you must do the following:
- Provide an allocated input locator pointer that represents a LOB that exists in the database tablespaces or external file system before you run the statement.
- SELECT a LOB locator into a LOB locator pointer variable.
- Use this variable in the embedded SQL LOB statement to access and manipulate the LOB value.
Table 8-9 Pro*C/C++ and Pro*COBOL Embedded SQL Statements for LOBs
| Category | Function/Procedure | Description |
|---|---|---|
| Open/Close | OPEN |
Open a LOB |
DESCRIBE[ISOPEN] |
Check is a LOB is open | |
CLOSE |
Close the LOB | |
| Read Operations | DESCRIBE[LENGTH] |
Get the length of the LOB |
DESCRIBE[CHUNKSIZE] |
Get the optimum read or write size | |
READ |
Read data from the LOB starting at a specified offset | |
| Modify Operations | WRITE |
Write data to the LOB at a specified offset |
WRITE APPEND |
Write data to the end of the LOB | |
ERASE |
Erase part of a LOB, starting at a specified offset | |
TRIM |
Trim the LOB value to the specified shorter length | |
| Operations involving multiple locators | APPEND |
Append a LOB value to another LOB |
COPY |
Copy all or part of a LOB to another LOB | |
ASSIGN |
Assign one LOB to another | |
LOAD FROM FILE |
Load BFILE data into a LOB
|