| SE_stream_describe_column | |
Describes a specified column for the given stream
LONG SE_stream_describe_column
(SE_STREAM stream,
SHORT column,
SE_COLUMN_DEF *column_def);
| stream | The stream handle |
| column | The column to describe |
| column_def | A structure containing the requested column definition |
SE_stream_describe_column describes a specified column for a given stream. Column numbers reference the column list from a given query or insert/update, not the table order. Column numbers are sequential, starting from one.
The resulting column definition is returned in an SE_COLUMN_DEF structure. Note: The SE_stream_describe_column function assumes that the application has allocated enough space for the SE_COLUMN_DEF structure.
typedef struct {
CHAR column_name[SE_MAX_COLUMN_LEN]; /* The column name */
LONG sde_type; /* The ArcSDE data type */
LONG size; /* The size of the column values */
SHORT decimal_digits; /* Number of digits after decimal */
BOOL nulls_allowed; /* Allows NULL values */
SHORT row_id_type; /* The column's row id type. This parameter
is read-only. ArcSDE sets it internally whenever
the table is described. */
} SE_COLUMN_DEF;
The column types (sde_type) are:
SE_SMALLINT_TYPE /* 2-byte integer */
SE_INTEGER_TYPE /* 4-byte integer */
SE_FLOAT_TYPE /* 4-byte float */
SE_DOUBLE_TYPE /* 8-byte float */
SE_STRING_TYPE /* Null term. Character array */
SE_BLOB_TYPE /* Variable length data */
SE_DATE_TYPE /* Struct tm date */
SE_SHAPE_TYPE /* Feature structure */
The row id types are:
SE_REGISTRATION_ROW_ID_COLUMN_TYPE_SDE
SE_REGISTRATION_ROW_ID_COLUMN_TYPE_USER
SE_REGISTRATION_ROW_ID_COLUMN_TYPE_NONE
SE_stream_describe_column can be called only after initializing a stream with a query or insert/update and before closing the stream.
SE_stream_describe_column is especially useful when an application is processing an end-user’s query without knowing the target table’s schema. After initializing the query, the application can determine the number of result columns with SE_stream_num_result_columns. The application calls SE_stream_describe_column for each result column. The information in the SE_COLUMN_DEF structure is used then to either bind output variables (using SE_stream_bind_output_column ) or to determine which SE_stream_get_* function to call after SE_stream_fetch.
SE_SUCCESS
SE_CONNECTION_IN_USE
SE_CONNECTION_LOCKED
SE_FUNCTION_SEQUENCE_ERROR
SE_INVALID_PARAM_VALUE
SE_INVALID_POINTER
SE_NOT_A_SELECT_STATEMENT
SE_SDE_NOT_STARTED