PostgreSQL与Java JDBC数据类型对照 源码

文件：postgresql-42.2.12.jar
类名：org.postgresql.jdbc.TypeInfoCache

 // basic pg types info:
  // 0 - type name
  // 1 - type oid
  // 2 - sql type
  // 3 - java class
  // 4 - array type oid
  private static final Object[][] types = {
      {"int2", Oid.INT2, Types.SMALLINT, "java.lang.Integer", Oid.INT2_ARRAY},
      {"int4", Oid.INT4, Types.INTEGER, "java.lang.Integer", Oid.INT4_ARRAY},
      {"oid", Oid.OID, Types.BIGINT, "java.lang.Long", Oid.OID_ARRAY},
      {"int8", Oid.INT8, Types.BIGINT, "java.lang.Long", Oid.INT8_ARRAY},
      {"money", Oid.MONEY, Types.DOUBLE, "java.lang.Double", Oid.MONEY_ARRAY},
      {"numeric", Oid.NUMERIC, Types.NUMERIC, "java.math.BigDecimal", Oid.NUMERIC_ARRAY},
      {"float4", Oid.FLOAT4, Types.REAL, "java.lang.Float", Oid.FLOAT4_ARRAY},
      {"float8", Oid.FLOAT8, Types.DOUBLE, "java.lang.Double", Oid.FLOAT8_ARRAY},
      {"char", Oid.CHAR, Types.CHAR, "java.lang.String", Oid.CHAR_ARRAY},
      {"bpchar", Oid.BPCHAR, Types.CHAR, "java.lang.String", Oid.BPCHAR_ARRAY},
      {"varchar", Oid.VARCHAR, Types.VARCHAR, "java.lang.String", Oid.VARCHAR_ARRAY},
      {"text", Oid.TEXT, Types.VARCHAR, "java.lang.String", Oid.TEXT_ARRAY},
      {"name", Oid.NAME, Types.VARCHAR, "java.lang.String", Oid.NAME_ARRAY},
      {"bytea", Oid.BYTEA, Types.BINARY, "[B", Oid.BYTEA_ARRAY},
      {"bool", Oid.BOOL, Types.BIT, "java.lang.Boolean", Oid.BOOL_ARRAY},
      {"bit", Oid.BIT, Types.BIT, "java.lang.Boolean", Oid.BIT_ARRAY},
      {"date", Oid.DATE, Types.DATE, "java.sql.Date", Oid.DATE_ARRAY},
      {"time", Oid.TIME, Types.TIME, "java.sql.Time", Oid.TIME_ARRAY},
      {"timetz", Oid.TIMETZ, Types.TIME, "java.sql.Time", Oid.TIMETZ_ARRAY},
      {"timestamp", Oid.TIMESTAMP, Types.TIMESTAMP, "java.sql.Timestamp", Oid.TIMESTAMP_ARRAY},
      {"timestamptz", Oid.TIMESTAMPTZ, Types.TIMESTAMP, "java.sql.Timestamp",
          Oid.TIMESTAMPTZ_ARRAY},
      //JCP! if mvn.project.property.postgresql.jdbc.spec >= "JDBC4.2"
      {"refcursor", Oid.REF_CURSOR, Types.REF_CURSOR, "java.sql.ResultSet", Oid.REF_CURSOR_ARRAY},
      //JCP! endif
      {"json", Oid.JSON, Types.OTHER, "org.postgresql.util.PGobject", Oid.JSON_ARRAY},
      {"point", Oid.POINT, Types.OTHER, "org.postgresql.geometric.PGpoint", Oid.POINT_ARRAY}
  };

  /**
   * PG maps several alias to real type names. When we do queries against pg_catalog, we must use
   * the real type, not an alias, so use this mapping.
   */
  private static final HashMap<String, String> typeAliases;

  static {
    typeAliases = new HashMap<String, String>();
    typeAliases.put("smallint", "int2");
    typeAliases.put("integer", "int4");
    typeAliases.put("int", "int4");
    typeAliases.put("bigint", "int8");
    typeAliases.put("float", "float8");
    typeAliases.put("boolean", "bool");
    typeAliases.put("decimal", "numeric");
  }