OCI Table Functions

Table 19-17 describes the OCI table functions that are described in this section.

Table 19-17 Table Functions

Function	Purpose
"OCITableDelete()"	Delete element
"OCITableExists()"	Test whether element exists
"OCITableFirst()"	Return first index of table
"OCITableLast()"	Return last index of table
"OCITableNext()"	Return next available index of table
"OCITablePrev()"	Return previous available index of table
"OCITableSize()"	Return current size of table

OCITableDelete()

Purpose

Deletes the element at the specified index.

Syntax

sword OCITableDelete ( OCIEnv          *env, 
                       OCIError        *err, 
                       sb4             index, 
                       OCITable        *tbl );

Parameters

env (IN/OUT): The OCI environment handle initialized in object mode.

See Also:
"OCIEnvCreate()", "OCIEnvNlsCreate()", and "OCIInitialize()" (deprecated)
err (IN/OUT): The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Obtain diagnostic information by calling OCIErrorGet().
index (IN): Index of the element that must be deleted.
tbl (IN): Table whose element is deleted.

Comments

This function returns an error if the element at the given index has already been deleted or if the given index is not valid for the given table.

Note:

The position ordinals of the remaining elements of the table are not changed by OCITableDelete(). The delete operation creates holes in the table.

Returns

An error is also returned if any input parameter is NULL.

Related Functions

OCIErrorGet(), OCITableExists()

OCITableExists()

Purpose

Tests whether an element exists at the given index.

Syntax

sword OCITableExists ( OCIEnv              *env,
                       OCIError            *err, 
                       const OCITable      *tbl,
                       sb4                 index, 
                       boolean             *exists );

Parameters

env (IN/OUT): The OCI environment handle initialized in object mode.

See Also:
"OCIEnvCreate()", "OCIEnvNlsCreate()", and "OCIInitialize()" (deprecated)
err (IN/OUT): The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Obtain diagnostic information by calling OCIErrorGet().
tbl (IN): Table in which the given index is checked.
index (IN): Index of the element that is checked for existence.
exists (OUT): Set to TRUE if the element at the given index exists; otherwise, it is set to FALSE.

Returns

This function returns an error if any input parameter is NULL.

Related Functions

OCIErrorGet(), OCITableDelete()

OCITableFirst()

Purpose

Returns the index of the first existing element in a given table.

Syntax

sword OCITableFirst ( OCIEnv             *env, 
                      OCIError           *err,
                      const OCITable     *tbl, 
                      sb4                *index  );

Parameters

env (IN/OUT): The OCI environment handle initialized in object mode.

See Also:
"OCIEnvCreate()", "OCIEnvNlsCreate()", and "OCIInitialize()" (deprecated)
err (IN/OUT): The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Obtain diagnostic information by calling OCIErrorGet().
tbl (IN): Table to scan.
index (OUT): First index of the element that exists in the given table that is returned.

Comments

If OCITableDelete() deletes the first five elements of a table, OCITableFirst() returns the value 6.

OCITableLast()

Purpose

Returns the index of the last existing element of a table.

Syntax

sword OCITableLast ( OCIEnv              *env, 
                     OCIError            *err, 
                     const OCITable      *tbl, 
                     sb4                 *index );

Parameters

env (IN/OUT): The OCI environment handle initialized in object mode.

See Also:
"OCIEnvCreate()", "OCIEnvNlsCreate()", and "OCIInitialize()" (deprecated)
err (IN/OUT): The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Obtain diagnostic information by calling OCIErrorGet().
tbl (IN): Table to scan.
index (OUT): Index of the last existing element in the table.

Comments

OCITableLast() returns the largest index numbered element in the index by integer collection.

Returns

This function returns an error if the table is empty.

Related Functions

OCIErrorGet(), OCITableFirst(), OCITableNext(), OCITablePrev()

OCITableNext()

Purpose

Returns the index of the next existing element of a table.

Syntax

sword OCITableNext ( OCIEnv             *env, 
                     OCIError           *err, 
                     sb4                index, 
                     const OCITable     *tbl, 
                     sb4                *next_index
                     boolean            *exists );

Parameters

env (IN/OUT): The OCI environment handle initialized in object mode.

See Also:
"OCIEnvCreate()", "OCIEnvNlsCreate()", and "OCIInitialize()" (deprecated)
err (IN/OUT): The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Obtain diagnostic information by calling OCIErrorGet().
index (IN): Index for the starting point of the scan.
tbl (IN): Table to scan.
next_index (OUT): Index of the next existing element after tbl(index).
exists (OUT): FALSE if no next index is available; otherwise, TRUE.

Returns

Returns the smallest position j, greater than index, such that exists(j) is TRUE.

OCITablePrev()

Purpose

Returns the index of the previous existing element of a table.

Syntax

sword OCITablePrev ( OCIEnv             *env, 
                     OCIError           *err, 
                     sb4                index,
                     const OCITable     *tbl,
                     sb4                *prev_index
                     boolean            *exists );

Parameters

env (IN/OUT): The OCI environment handle initialized in object mode.

See Also:
"OCIEnvCreate()", "OCIEnvNlsCreate()", and "OCIInitialize()" (deprecated)
err (IN/OUT): The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Obtain diagnostic information by calling OCIErrorGet().
index (IN): Index for the starting point of the scan.
tbl (IN): Table to scan.
prev_index (OUT): Index of the previous existing element before tbl(index).
exists (OUT): FALSE if no previous index is available; otherwise, TRUE.

Returns

Returns the largest position j, less than index, such that exists (j) is TRUE.

OCITableSize()

Purpose

Returns the size of the given table, not including any holes created by deleted elements.

Syntax

sword OCITableSize ( OCIEnv             *env,
                     OCIError           *err,
                     const OCITable     *tbl
                     sb4                *size );

Parameters

env (IN/OUT): The OCI environment handle initialized in object mode.

See Also:
, "OCIEnvNlsCreate()","OCIEnvCreate()" and "OCIInitialize()" (deprecated)
err (IN/OUT): The OCI error handle. If there is an error, it is recorded in err, and this function returns OCI_ERROR. Obtain diagnostic information by calling OCIErrorGet().
tbl (IN): Nested table whose number of elements is returned.
size (OUT): Current number of elements in the nested table. The count does not include deleted elements.

Comments

The count is decremented when elements are deleted from the nested table. So this count does not include any holes created by deleting elements. To get the count including the holes created by the deleted elements, use OCICollSize().

Example 19-4 shows a code fragment where an element is deleted from a nested table.

Example 19-4 Deleting an Element from a Nested table

OCITableSize(...); 
// assume 'size' returned is equal to 5
OCITableDelete(...); // delete one element
OCITableSize(...);
// 'size' returned is equal to 4

To get the count plus the count of deleted elements, use OCICollSize(), as shown in Example 19-5. Continuing Example 19-4.

Example 19-5 Getting a Count of All Elements Including Deleted Elements from a Nested Table

OCICollSize(...)
// 'size' returned is still equal to 5

Returns

This function returns an error if an error occurs during the loading of the nested table into the object cache, or if any of the input parameters is NULL.

Related Functions

OCIErrorGet(), OCICollSize()