DBMS_SQL¶

Related Interfaces¶

Table 1 lists interfaces supported by the DBMS_SQL package.

**Table 1** DBMS_SQL¶
API	Description
DBMS_SQL.OPEN_CURSOR	Opens a cursor.
DBMS_SQL.CLOSE_CURSOR	Closes an open cursor.
DBMS_SQL.PARSE	Transmits a group of SQL statements to a cursor. Currently, only the SELECT statement is supported.
DBMS_SQL.EXECUTE	Performs a set of dynamically defined operations on the cursor.
DBMS_SQL.FETCHE_ROWS	Reads a row of cursor data.
DBMS_SQL.DEFINE_COLUMN	Dynamically defines a column.
DBMS_SQL.DEFINE_COLUMN_CHAR	Dynamically defines a column of the CHAR type.
DBMS_SQL.DEFINE_COLUMN_INT	Dynamically defines a column of the INT type.
DBMS_SQL.DEFINE_COLUMN_LONG	Dynamically defines a column of the LONG type.
DBMS_SQL.DEFINE_COLUMN_RAW	Dynamically defines a column of the RAW type.
DBMS_SQL.DEFINE_COLUMN_TEXT	Dynamically defines a column of the TEXT type.
DBMS_SQL.DEFINE_COLUMN_UNKNOWN	Dynamically defines a column of an unknown type.
DBMS_SQL.COLUMN_VALUE	Reads a dynamically defined column value.
DBMS_SQL.COLUMN_VALUE_CHAR	Reads a dynamically defined column value of the CHAR type.
DBMS_SQL.COLUMN_VALUE_INT	Reads a dynamically defined column value of the INT type.
DBMS_SQL.COLUMN_VALUE_LONG	Reads a dynamically defined column value of the LONG type.
DBMS_SQL.COLUMN_VALUE_RAW	Reads a dynamically defined column value of the RAW type.
DBMS_SQL.COLUMN_VALUE_TEXT	Reads a dynamically defined column value of the TEXT type.
DBMS_SQL.COLUMN_VALUE_UNKNOWN	Reads a dynamically defined column value of an unknown type.
DBMS_SQL.IS_OPEN	Checks whether a cursor is opened.

Note

You are advised to use dbms_sql.define_column and dbms_sql.column_value to define columns.
If the size of the result set is greater than the value of work_mem, the result set will be flushed to disk. The value of work_mem must be no greater than 512 MB.

DBMS_SQL.OPEN_CURSOR
This function opens a cursor and is the prerequisite for the subsequent dbms_sql operations. This function does not transfer any parameter. It automatically generates cursor IDs in an ascending order and returns values to integer variables.
The function prototype of DBMS_SQL.OPEN_CURSOR is:
```
DBMS_SQL.OPEN_CURSOR (
)
RETURN INTEGER;
```
DBMS_SQL.CLOSE_CURSOR
This function closes a cursor. It is the end of each dbms_sql operation. If this function is not invoked when the stored procedure ends, the memory is still occupied by the cursor. Therefore, remember to close a cursor when you do not need to use it. If an exception occurs, the stored procedure exits but the cursor is not closed. Therefore, you are advised to include this interface in the exception handling of the stored procedure.
The function prototype of DBMS_SQL.CLOSE_CURSOR is:
```
DBMS_SQL.CLOSE_CURSOR (
cursorid     IN INTEGER
)
RETURN INTEGER;
```
Table 2 DBMS_SQL.CLOSE_CURSOR interface parameters¶
Parameter Name
Description
cursorid
ID of the cursor to be closed

**Table 2** DBMS_SQL.CLOSE_CURSOR interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be closed

DBMS_SQL.PARSE

This function parses the query statement of a given cursor. The input query statement is executed immediately. Currently, only the SELECT query statement can be parsed. The statement parameters can be transferred only through the TEXT type. The length cannot exceed 1 GB.

The function prototype of DBMS_SQL.PARSE is:

DBMS_SQL.PARSE (
cursorid     IN INTEGER,
query_string IN TEXT,
label        IN INTEGER
)
RETURN BOOLEAN;

**Table 3** DBMS_SQL.PARSE interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor whose query statement is parsed
query_string	Query statements to be parsed
language_flag	Version language number. Currently, only 1 is supported.

DBMS_SQL.EXECUTE
This function executes a given cursor. This function receives a cursor ID. The obtained data after is used for subsequent operations. Currently, only the SELECT query statement can be executed.
The function prototype of DBMS_SQL.EXECUTE is:
```
DBMS_SQL.EXECUTE(
cursorid     IN INTEGER,
)
RETURN INTEGER;
```
Table 4 DBMS_SQL.EXECUTE interface parameters¶
Parameter Name
Description
cursorid
ID of the cursor whose query statement is parsed
DBMS_SQL.FETCHE_ROWS
This function returns the number of data rows that meet query conditions. Each time the interface is executed, the system obtains a set of new rows until all data is read.
The function prototype of DBMS_SQL.FETCHE_ROWS is:
```
DBMS_SQL.FETCHE_ROWS(
cursorid     IN INTEGER,
)
RETURN INTEGER;
```
Table 5 DBMS_SQL.FETCH_ROWS interface parameters¶
Parameter Name
Description
curosorid
ID of the cursor to be executed

**Table 5** DBMS_SQL.FETCH_ROWS interface parameters¶
Parameter Name	Description
curosorid	ID of the cursor to be executed

DBMS_SQL.DEFINE_COLUMN

This function defines columns returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

The function prototype of DBMS_SQL.DEFINE_COLUMN is:

DBMS_SQL.DEFINE_COLUMN(
cursorid     IN INTEGER,
position     IN INTEGER,
column_ref   IN ANYELEMENT,
column_size     IN INTEGER default 1024
)
RETURN INTEGER;

**Table 6** DBMS_SQL.DEFINE_COLUMN interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column_ref	Variable of any type. You can select an appropriate interface to dynamically define columns based on variable types.
column_size	Length of a defined column

DBMS_SQL.DEFINE_COLUMN_CHAR

This function defines columns of the CHAR type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

The function prototype of DBMS_SQL.DEFINE_COLUMN_CHAR is:

DBMS_SQL.DEFINE_COLUMN_CHAR(
cursorid     IN INTEGER,
position     IN INTEGER,
column       IN TEXT,
column_size     IN INTEGER
)
RETURN INTEGER;

**Table 7** DBMS_SQL.DEFINE_COLUMN_CHAR interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column	Parameter to be defined
column_size	Length of a dynamically defined column

DBMS_SQL.DEFINE_COLUMN_INT
This function defines columns of the INT type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.
The function prototype of DBMS_SQL.DEFINE_COLUMN_INT is:
```
DBMS_SQL.DEFINE_COLUMN_INT(
cursorid     IN INTEGER,
position     IN INTEGER
)
RETURN INTEGER;
```
Table 8 DBMS_SQL.DEFINE_COLUMN_INT interface parameters¶
Parameter Name
Description
cursorid
ID of the cursor to be executed
position
Position of a dynamically defined column in the query
DBMS_SQL.DEFINE_COLUMN_LONG
This function defines columns of a long type (not LONG) returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type. The maximum size of a long column is 1 GB.
The function prototype of DBMS_SQL.DEFINE_COLUMN_LONG is:
```
DBMS_SQL.DEFINE_COLUMN_LONG(
cursorid     IN INTEGER,
position     IN INTEGER
)
RETURN INTEGER;
```
Table 9 DBMS_SQL.DEFINE_COLUMN_LONG interface parameters¶
Parameter Name
Description
cursorid
ID of the cursor to be executed
position
Position of a dynamically defined column in the query

DBMS_SQL.DEFINE_COLUMN_RAW

This function defines columns of the RAW type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

The function prototype of DBMS_SQL.DEFINE_COLUMN_RAW is:

DBMS_SQL.DEFINE_COLUMN_RAW(
cursorid     IN INTEGER,
position     IN INTEGER,
column       IN BYTEA,
column_size     IN INTEGER
)
RETURN INTEGER;

**Table 10** DBMS_SQL.DEFINE_COLUMN_RAW interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column	Parameter of the RAW type
column_size	Column length

DBMS_SQL.DEFINE_COLUMN_TEXT

This function defines columns of the TEXT type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

The function prototype of DBMS_SQL.DEFINE_COLUMN_TEXT is:

DBMS_SQL.DEFINE_COLUMN_CHAR(
cursorid     IN INTEGER,
position     IN INTEGER,
max_size     IN INTEGER
)
RETURN INTEGER;

**Table 11** DBMS_SQL.DEFINE_COLUMN_TEXT interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
max_size	Maximum length of the defined TEXT type

DBMS_SQL.DEFINE_COLUMN_UNKNOWN

This function processes columns of unknown data types returned from a given cursor and is used only for the system to report an error and exist when the type cannot be identified.

The function prototype of DBMS_SQL.DEFINE_COLUMN_UNKNOWN is:

DBMS_SQL.DEFINE_COLUMN_CHAR(
cursorid     IN INTEGER,
position     IN INTEGER,
column       IN TEXT
)
RETURN INTEGER;

**Table 12** DBMS_SQL.DEFINE_COLUMN_UNKNOWN interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column	Dynamically defined parameter

DBMS_SQL.COLUMN_VALUE

This function returns the cursor element value specified by a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

The function prototype of DBMS_SQL.COLUMN_VALUE is:

DBMS_SQL.COLUMN_VALUE(
cursorid                 IN    INTEGER,
position                 IN    INTEGER,
column_value             INOUT ANYELEMENT
)
RETURN ANYELEMENT;

**Table 13** DBMS_SQL.COLUMN_VALUE interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column_value	Return value of a defined column

DBMS_SQL.COLUMN_VALUE_CHAR

This function returns the value of the CHAR type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

The function prototype of DBMS_SQL.COLUMN_VALUE_CHAR is:

DBMS_SQL.COLUMN_VALUE_CHAR(
cursorid                 IN    INTEGER,
position                 IN    INTEGER,
column_value             INOUT CHARACTER,
err_num                  INOUT NUMERIC default 0,
actual_length            INOUT INTEGER default 1024
)
RETURN RECORD;

**Table 14** DBMS_SQL.COLUMN_VALUE_CHAR interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column_value	Return value
err_num	Error No. It is an output parameter and the argument must be a variable. Currently, the output value is -1 regardless of the argument.
actual_length	Length of a return value

DBMS_SQL.COLUMN_VALUE_INT
This function returns the value of the INT type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS. The function prototype of DBMS_SQL.COLUMN_VALUE_INT is:
```
DBMS_SQL.COLUMN_VALUE_INT(
cursorid                 IN    INTEGER,
position                 IN    INTEGER
)
RETURN INTEGER;
```
Table 15 DBMS_SQL.COLUMN_VALUE_INT interface parameters¶
Parameter Name
Description
cursorid
ID of the cursor to be executed
position
Position of a dynamically defined column in the query

DBMS_SQL.COLUMN_VALUE_LONG

This function returns the value of a long type (not LONG or BIGINT) in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

The function prototype of DBMS_SQL.COLUMN_VALUE_LONG is:

DBMS_SQL.COLUMN_VALUE_LONG(
cursorid                 IN    INTEGER,
position                 IN    INTEGER,
length                   IN    INTEGER,
off_set                  IN    INTEGER,
column_value             INOUT TEXT,
actual_length            INOUT INTEGER default 1024
)
RETURN RECORD;

**Table 16** DBMS_SQL.COLUMN_VALUE_LONG interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
length	Length of a return value
off_set	Start position of a return value
column_value	Return value
actual_length	Length of a return value

DBMS_SQL.COLUMN_VALUE_RAW

This function returns the value of the RAW type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

The function prototype of DBMS_SQL.COLUMN_VALUE_RAW is:

DBMS_SQL.COLUMN_VALUE_RAW(
cursorid                 IN    INTEGER,
position                 IN    INTEGER,
column_value             INOUT BYTEA,
err_num                  INOUT NUMERIC default 0,
actual_length            INOUT INTEGER default 1024
)
RETURN RECORD;

**Table 17** DBMS_SQL.COLUMN_VALUE_RAW interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column_value	Returned column value
err_num	Error No. It is an output parameter and the argument must be a variable. Currently, the output value is -1 regardless of the argument.
actual_length	Length of a return value. The value longer than this length will be truncated.

DBMS_SQL.COLUMN_VALUE_TEXT
This function returns the value of the TEXT type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.
The function prototype of DBMS_SQL.COLUMN_VALUE_TEXT is:
```
DBMS_SQL.COLUMN_VALUE_TEXT(
cursorid                 IN    INTEGER,
position                 IN    INTEGER
)
RETURN TEXT;
```
Table 18 DBMS_SQL.COLUMN_VALUE_TEXT interface parameters¶
Parameter Name
Description
cursorid
ID of the cursor to be executed
position
Position of a dynamically defined column in the query

DBMS_SQL.COLUMN_VALUE_UNKNOWN

This function returns the value of an unknown type in a specified position of a cursor. This is an error handling interface when the type is not unknown.

The function prototype of DBMS_SQL.COLUMN_VALUE_UNKNOWN is:

DBMS_SQL.COLUMN_VALUE_UNKNOWN(
cursorid                 IN    INTEGER,
position                 IN    INTEGER,
COLUMN_TYPE              IN    TEXT
)
RETURN TEXT;

**Table 19** DBMS_SQL.COLUMN_VALUE_UNKNOWN interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be executed
position	Position of a dynamically defined column in the query
column_type	Returned parameter type

DBMS_SQL.IS_OPEN

This function returns the status of a cursor: open, parse, execute, or define. The value is TRUE. If the status is unknown, an error is reported. In other cases, the value is FALSE.

The function prototype of DBMS_SQL.IS_OPEN is:

DBMS_SQL.IS_OPEN(
cursorid                 IN    INTEGER
)
RETURN BOOLEAN;

**Table 20** DBMS_SQL.IS_OPEN interface parameters¶
Parameter Name	Description
cursorid	ID of the cursor to be queried

Examples¶

-- Perform operations on RAW data in a stored procedure.
create or replace procedure pro_dbms_sql_all_02(in_raw raw,v_in int,v_offset int)
as
cursorid int;
v_id int;
v_info bytea :=1;
query varchar(2000);
execute_ret int;
define_column_ret_raw bytea :='1';
define_column_ret int;
begin
drop table if exists pro_dbms_sql_all_tb1_02 ;
create table pro_dbms_sql_all_tb1_02(a int ,b blob);
insert into pro_dbms_sql_all_tb1_02 values(1,HEXTORAW('DEADBEEE'));
insert into pro_dbms_sql_all_tb1_02 values(2,in_raw);
query := 'select * from pro_dbms_sql_all_tb1_02 order by 1';
-- Open a cursor.
cursorid := dbms_sql.open_cursor();
-- Compile the cursor.
dbms_sql.parse(cursorid, query, 1);
-- Define a column.
define_column_ret:= dbms_sql.define_column(cursorid,1,v_id);
define_column_ret_raw:= dbms_sql.define_column_raw(cursorid,2,v_info,10);
-- Execute the cursor.
execute_ret := dbms_sql.execute(cursorid);
loop
exit when (dbms_sql.fetch_rows(cursorid) <= 0);
-- Obtain values.
dbms_sql.column_value(cursorid,1,v_id);
dbms_sql.column_value_raw(cursorid,2,v_info,v_in,v_offset);
-- Output the result.
dbms_output.put_line('id:'|| v_id || ' info:' || v_info);
end loop;
-- Close the cursor.
dbms_sql.close_cursor(cursorid);
end;
/
-- Invoke the stored procedure.
call pro_dbms_sql_all_02(HEXTORAW('DEADBEEF'),0,1);

-- Delete the stored procedure.
DROP PROCEDURE pro_dbms_sql_all_02;

last updated: 2024-11-13 15:46 UTC - commit: bdcb01d62e4f1de672b662d88ef6cb8eb3a27a29