The ST_WKBToSQL() function
The ST_WKBToSQL() function constructs
an ST_Geometry given its well-known binary representation. The SRID
of the ST_Geometry is 0
.
Syntax
ST_WKBToSQL(WKBGeometry lvarchar)
Return type
ST_Geometry
Example
The following CREATE TABLE statement
creates the lots table, which has two columns: lot_id,
which uniquely identifies each lot, and the lot polygon column,
which contains the geometry of each lot:
CREATE TABLE lots (lot_id integer,
lot ST_MultiPolygon);
The following C code fragment contains ODBC functions included with the spatial data type functions that insert data into the lots table.
The ST_WKBToSQL() function
converts WKB representations intoHCL®
OneDB® spatial
geometry. The entire INSERT statement is copied into the sql_stmt string.
The INSERT statement contains parameter markers to accept the lot_id data
and the lot data, dynamically:
/* Create the SQL insert statement to populate the lots table.
* The question marks are parameter markers that indicate the
* column values that will be inserted at run time. */
sprintf(sql_stmt,
"INSERT INTO lots (lot_id, lot) "
"VALUES (?, ST_WKBToSQL(?))");
/* Prepare the SQL statement for execution */
rc = SQLPrepare (hstmt, (unsigned char *)sql_stmt, SQL_NTS);
/* Bind the lot_id to the first parameter. */
pcbvalue1 = 0;
rc = SQLBindParameter (hstmt, 1, SQL_PARAM_INPUT, SQL_C_SLONG,
SQL_INTEGER, 0, 0,
&lot_id, 0, &pcbvalue1);
/* Bind the lot geometry to the second parameter. */
pcbvalue2 = lot_wkb_len;
rc = SQLBindParameter (hstmt, 2, SQL_PARAM_INPUT, SQL_C_BINARY,
SQL_INFX_UDT_LVARCHAR, lot_wkb_len, 0,
lot_wkb_buf, lot_wkb_len, &pcbvalue2);
/* Execute the insert statement. */
rc = SQLExecute (hstmt);