Populating an Array Descriptor

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There are four ways to populate an array descriptor:

• Call isc_array_lookup_desc2(), which looks up (in the system metadata tables) and stores in an array descriptor the data type, length, scale, and dimensions for a specified array column in a specified table. This function also stores the table and column name in the descriptor, and initializes its array_desc_flags field to indicate that the array is to be accessed in row-major order. For example,

isc_array_lookup_desc2( status_vector,
&db_handle, /* Set by isc_attach_database() */
&tr_handle, /* Set by isc_start_transaction() */
"PROJ_DEPT_BUDGET", /* table name */
"QUART_HEAD_CNT", /* array column name */
&desc); /* descriptor to be filled in */

• Call isc_array_lookup_bounds2(), which is like a call to ­isc_array_lookup_desc2(), except that ­isc_array_lookup_bounds2() also looks up and stores into the array descriptor the upper and lower bounds of each dimension.
• Call isc_array_set_desc2(), which initializes the descriptor from parameters, rather than by accessing the database metadata. For example,

short dtype = SQL_TEXT;
short len = 8;
short numdims = 2;
isc_array_set_desc2( status_vector,
"TABLE1", /* table name */
"CHAR_ARRAY", /* array column name */
&dtype, /* data type of elements */
&len, /* length of each element */
&numdims, /* number of array dimensions */
&desc); /* descriptor to be filled in */

• Set the descriptor fields directly. An example of setting the array_desc_dimensions field of the descriptor, desc, is:

desc.array_desc_dimensions = 2;

For complete syntax and information about isc_array_lookup_bounds2(), ­isc_array_lookup_desc2(), and isc_array_set_desc2(), see API Function Reference.