Examples with TableFunction org.apache.calcite.schema.TableFunction used on opensource projects

Example 1 with TableFunction

use of org.apache.calcite.schema.TableFunction in project calcite by apache.

the class ModelHandler method addFunctions.

/**
 * Creates and validates a {@link ScalarFunctionImpl}, and adds it to a
 * schema. If {@code methodName} is "*", may add more than one function.
 *
 * @param schema Schema to add to
 * @param functionName Name of function; null to derived from method name
 * @param path Path to look for functions
 * @param className Class to inspect for methods that may be user-defined
 *                  functions
 * @param methodName Method name;
 *                  null means use the class as a UDF;
 *                  "*" means add all methods
 * @param upCase Whether to convert method names to upper case, so that they
 *               can be called without using quotes
 */
public static void addFunctions(SchemaPlus schema, String functionName, List<String> path, String className, String methodName, boolean upCase) {
    final Class<?> clazz;
    try {
        clazz = Class.forName(className);
    } catch (ClassNotFoundException e) {
        throw new RuntimeException("UDF class '" + className + "' not found");
    }
    final TableFunction tableFunction = TableFunctionImpl.create(clazz, Util.first(methodName, "eval"));
    if (tableFunction != null) {
        schema.add(functionName, tableFunction);
        return;
    }
    // Must look for TableMacro before ScalarFunction. Both have an "eval"
    // method.
    final TableMacro macro = TableMacroImpl.create(clazz);
    if (macro != null) {
        schema.add(functionName, macro);
        return;
    }
    if (methodName != null && methodName.equals("*")) {
        for (Map.Entry<String, ScalarFunction> entry : ScalarFunctionImpl.createAll(clazz).entries()) {
            String name = entry.getKey();
            if (upCase) {
                name = name.toUpperCase(Locale.ROOT);
            }
            schema.add(name, entry.getValue());
        }
        return;
    } else {
        final ScalarFunction function = ScalarFunctionImpl.create(clazz, Util.first(methodName, "eval"));
        if (function != null) {
            final String name;
            if (functionName != null) {
                name = functionName;
            } else if (upCase) {
                name = methodName.toUpperCase(Locale.ROOT);
            } else {
                name = methodName;
            }
            schema.add(name, function);
            return;
        }
    }
    if (methodName == null) {
        final AggregateFunction aggFunction = AggregateFunctionImpl.create(clazz);
        if (aggFunction != null) {
            schema.add(functionName, aggFunction);
            return;
        }
    }
    throw new RuntimeException("Not a valid function class: " + clazz + ". Scalar functions and table macros have an 'eval' method; " + "aggregate functions have 'init' and 'add' methods, and optionally " + "'initAdd', 'merge' and 'result' methods.");
}

Example 2 with TableFunction

use of org.apache.calcite.schema.TableFunction in project calcite by apache.

the class JdbcTest method adviseSql.

private void adviseSql(String sql, Function<ResultSet, Void> checker) throws ClassNotFoundException, SQLException {
    Properties info = new Properties();
    info.put("lex", "JAVA");
    info.put("quoting", "DOUBLE_QUOTE");
    Connection connection = DriverManager.getConnection("jdbc:calcite:", info);
    CalciteConnection calciteConnection = connection.unwrap(CalciteConnection.class);
    SchemaPlus rootSchema = calciteConnection.getRootSchema();
    rootSchema.add("hr", new ReflectiveSchema(new HrSchema()));
    SchemaPlus schema = rootSchema.add("s", new AbstractSchema());
    calciteConnection.setSchema("hr");
    final TableFunction table = new SqlAdvisorGetHintsFunction();
    schema.add("get_hints", table);
    PreparedStatement ps = connection.prepareStatement("select *\n" + "from table(\"s\".\"get_hints\"(?, ?)) as t(id, names, type)");
    SqlParserUtil.StringAndPos sap = SqlParserUtil.findPos(sql);
    ps.setString(1, sap.sql);
    ps.setInt(2, sap.cursor);
    final ResultSet resultSet = ps.executeQuery();
    checker.apply(resultSet);
    resultSet.close();
    connection.close();
}

Example 3 with TableFunction

use of org.apache.calcite.schema.TableFunction in project calcite by apache.

the class TableFunctionTest method testTableFunction.

/**
 * Tests a table function with literal arguments.
 */
@Test
public void testTableFunction() throws SQLException, ClassNotFoundException {
    Connection connection = DriverManager.getConnection("jdbc:calcite:");
    CalciteConnection calciteConnection = connection.unwrap(CalciteConnection.class);
    SchemaPlus rootSchema = calciteConnection.getRootSchema();
    SchemaPlus schema = rootSchema.add("s", new AbstractSchema());
    final TableFunction table = TableFunctionImpl.create(Smalls.GENERATE_STRINGS_METHOD);
    schema.add("GenerateStrings", table);
    ResultSet resultSet = connection.createStatement().executeQuery("select *\n" + "from table(\"s\".\"GenerateStrings\"(5)) as t(n, c)\n" + "where char_length(c) > 3");
    assertThat(CalciteAssert.toString(resultSet), equalTo("N=4; C=abcd\n"));
}

Example 4 with TableFunction

use of org.apache.calcite.schema.TableFunction in project calcite by apache.

the class TableFunctionTest method getConnectionWithMultiplyFunction.

private Connection getConnectionWithMultiplyFunction() throws ClassNotFoundException, SQLException {
    Connection connection = DriverManager.getConnection("jdbc:calcite:");
    CalciteConnection calciteConnection = connection.unwrap(CalciteConnection.class);
    SchemaPlus rootSchema = calciteConnection.getRootSchema();
    SchemaPlus schema = rootSchema.add("s", new AbstractSchema());
    final TableFunction table = TableFunctionImpl.create(Smalls.MULTIPLICATION_TABLE_METHOD);
    schema.add("multiplication", table);
    return connection;
}

Example 5 with TableFunction

use of org.apache.calcite.schema.TableFunction in project calcite by apache.

the class TableFunctionTest method testScannableTableFunction.

/**
 * Tests a table function that implements {@link ScannableTable} and returns
 * a single column.
 */
@Test
public void testScannableTableFunction() throws SQLException, ClassNotFoundException {
    Connection connection = DriverManager.getConnection("jdbc:calcite:");
    CalciteConnection calciteConnection = connection.unwrap(CalciteConnection.class);
    SchemaPlus rootSchema = calciteConnection.getRootSchema();
    SchemaPlus schema = rootSchema.add("s", new AbstractSchema());
    final TableFunction table = TableFunctionImpl.create(Smalls.MAZE_METHOD);
    schema.add("Maze", table);
    final String sql = "select *\n" + "from table(\"s\".\"Maze\"(5, 3, 1))";
    ResultSet resultSet = connection.createStatement().executeQuery(sql);
    final String result = "S=abcde\n" + "S=xyz\n" + "S=generate(w=5, h=3, s=1)\n";
    assertThat(CalciteAssert.toString(resultSet), is(result));
}