Returns a copy of the point with the X coordinate set to the specified xcoord value.
      Syntax
         
            point-expression.ST_X(DOUBLE xcoord)
      
      Parameters
         
            - 
               xcoord – 
               The new X coordinate value.
            
Returns
         ST_Point Returns a copy of the point with the X coordinate set to the specified xcoord value.
      Standards
         
            SQL/MM (ISO/IEC 13249-3: 2006) 6.1.3