如何使用MyBatis从PostGIS查询列的子集？

Question

I'm trying to query data from a PostGIS database using MyBatis, ignoring the geospatial data. I have the following table in the database:

CREATE TABLE salesgeometry
(
  id bigint NOT NULL,
  label character varying(255),
  type character varying(255),
  geom geometry,
  CONSTRAINT salesgeometry_pkey PRIMARY KEY (id ),
  CONSTRAINT enforce_dims_geom CHECK (st_ndims(geom) = 2),
  CONSTRAINT enforce_srid_geom CHECK (st_srid(geom) = 4326)
)

I'm trying to map this with MyBatis using this annotation:

@Select("SELECT id, type, label FROM salesgeometry WHERE ST_Within(" +
        "ST_GeomFromText('POINT(#{longitude} #{latitude})', 4326), geom) " +
        "AND type = #{type}")
Geometry getGeometryAtLocation(
        @NotNull @Param("type") String geometryType,
        @NotNull @Param("longitude") BigDecimal longitude, 
        @NotNull @Param("latitude") BigDecimal latitude
);

And the target class has fields like this:

public class Geometry {
    private long id;
    private String type;
    private String label;
    ...
}

Unfortunately this does not work, instead I get a

org.postgresql.util.PSQLException: The column index is out of range: 2, number of columns: 1.

How do I query just the subset of columns from the database?

Answer 1

The problem is that ST_GeomFromText('POINT(#{longitude} #{latitude})', 4326) is mapped by MyBatis to a prepared statement looking like this: ST_GeomFromText('POINT(? ?)', 4326) , which doesn't actually contain the expected parameters since the question marks are within quotes.

The solution is to either use string concatenation (as in ST_GeomFromText('POINT(' || #{longitude} || ' ' || #{latitude} || ')', 4326) or use string substitution instead: ST_GeomFromText('POINT(${longitude} ${latitude})', 4326) , which puts the values into the SQL statement directly instead of using parameters of prepared statements.

The following mapping works (note the two dollar symbols for longitude and latitude):

@Select("SELECT id, type, label FROM salesgeometry WHERE ST_Within(" +
        "ST_GeomFromText('POINT(${longitude} ${latitude})', 4326), geom) " +
        "AND type = #{type}")
Geometry getGeometryAtLocation(
        @NotNull @Param("type") String geometryType,
        @NotNull @Param("longitude") BigDecimal longitude, 
        @NotNull @Param("latitude") BigDecimal latitude
);