mihaibudiu commented on code in PR #4342: URL: https://github.com/apache/calcite/pull/4342#discussion_r2064191222
########## core/src/main/java/org/apache/calcite/sql/dialect/DuckDBSqlDialect.java: ########## @@ -0,0 +1,157 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to you under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.calcite.sql.dialect; + +import org.apache.calcite.avatica.util.TimeUnitRange; +import org.apache.calcite.config.NullCollation; +import org.apache.calcite.rel.type.RelDataTypeSystem; +import org.apache.calcite.rel.type.RelDataTypeSystemImpl; +import org.apache.calcite.sql.SqlCall; +import org.apache.calcite.sql.SqlDialect; +import org.apache.calcite.sql.SqlLiteral; +import org.apache.calcite.sql.SqlWriter; +import org.apache.calcite.sql.fun.SqlLibraryOperators; +import org.apache.calcite.sql.parser.SqlParserPos; +import org.apache.calcite.sql.type.SqlTypeName; + +/** + * A <code>SqlDialect</code> implementation for the DuckDB database. + */ +public class DuckDBSqlDialect extends StarRocksSqlDialect { + public static final RelDataTypeSystem TYPE_SYSTEM = + new RelDataTypeSystemImpl() { + + // We can refer to document of DuckDB 1.2.x: + // https://duckdb.org/docs/stable/sql/data_types/numeric#fixed-point-decimals + @Override public int getMaxPrecision(SqlTypeName typeName) { + switch (typeName) { + case DECIMAL: + return 38; + default: + return super.getMaxPrecision(typeName); + } + } + + @Override public int getMaxScale(SqlTypeName typeName) { + switch (typeName) { + case DECIMAL: + return 38; + default: + return super.getMaxScale(typeName); + } + } + + @Override public int getMaxNumericScale() { + return getMaxScale(SqlTypeName.DECIMAL); + } + }; + + public static final SqlDialect.Context DEFAULT_CONTEXT = SqlDialect.EMPTY_CONTEXT + .withDatabaseProduct(SqlDialect.DatabaseProduct.DUCKDB) + .withIdentifierQuoteString("\"") + .withNullCollation(NullCollation.LAST) Review Comment: Is this LAST or HIGH? These are not the same. ########## core/src/main/java/org/apache/calcite/sql/dialect/DuckDBSqlDialect.java: ########## @@ -0,0 +1,157 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to you under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.calcite.sql.dialect; + +import org.apache.calcite.avatica.util.TimeUnitRange; +import org.apache.calcite.config.NullCollation; +import org.apache.calcite.rel.type.RelDataTypeSystem; +import org.apache.calcite.rel.type.RelDataTypeSystemImpl; +import org.apache.calcite.sql.SqlCall; +import org.apache.calcite.sql.SqlDialect; +import org.apache.calcite.sql.SqlLiteral; +import org.apache.calcite.sql.SqlWriter; +import org.apache.calcite.sql.fun.SqlLibraryOperators; +import org.apache.calcite.sql.parser.SqlParserPos; +import org.apache.calcite.sql.type.SqlTypeName; + +/** + * A <code>SqlDialect</code> implementation for the DuckDB database. + */ +public class DuckDBSqlDialect extends StarRocksSqlDialect { + public static final RelDataTypeSystem TYPE_SYSTEM = + new RelDataTypeSystemImpl() { + + // We can refer to document of DuckDB 1.2.x: + // https://duckdb.org/docs/stable/sql/data_types/numeric#fixed-point-decimals + @Override public int getMaxPrecision(SqlTypeName typeName) { + switch (typeName) { + case DECIMAL: + return 38; + default: + return super.getMaxPrecision(typeName); + } + } + + @Override public int getMaxScale(SqlTypeName typeName) { + switch (typeName) { + case DECIMAL: + return 38; + default: + return super.getMaxScale(typeName); + } + } + + @Override public int getMaxNumericScale() { + return getMaxScale(SqlTypeName.DECIMAL); + } + }; + + public static final SqlDialect.Context DEFAULT_CONTEXT = SqlDialect.EMPTY_CONTEXT + .withDatabaseProduct(SqlDialect.DatabaseProduct.DUCKDB) + .withIdentifierQuoteString("\"") + .withNullCollation(NullCollation.LAST) + .withDataTypeSystem(TYPE_SYSTEM); + + public static final SqlDialect DEFAULT = new DuckDBSqlDialect(DEFAULT_CONTEXT); + + /** Creates a DuckDBSqlDialect. */ + public DuckDBSqlDialect(SqlDialect.Context context) { + super(context); + } + + @Override public boolean supportsApproxCountDistinct() { + return true; + } + + @Override public void unparseCall(SqlWriter writer, SqlCall call, + int leftPrec, int rightPrec) { + switch (call.getKind()) { + case MAP_VALUE_CONSTRUCTOR: + writer.keyword(call.getOperator().getName()); + final SqlWriter.Frame mapFrame = writer.startList("{", "}"); + for (int i = 0; i < call.operandCount(); i++) { + String sep = i % 2 == 0 ? "," : ":"; + writer.sep(sep); + call.operand(i).unparse(writer, leftPrec, rightPrec); + } + writer.endList(mapFrame); + break; + case FLOOR: + if (call.operandCount() != 2) { + super.unparseCall(writer, call, leftPrec, rightPrec); + return; + } + unparseFloor(writer, call); + break; + case CHAR_LENGTH: + SqlCall lengthCall = SqlLibraryOperators.LENGTH + .createCall(SqlParserPos.ZERO, call.getOperandList()); + super.unparseCall(writer, lengthCall, leftPrec, rightPrec); + break; + default: + super.unparseCall(writer, call, leftPrec, rightPrec); + } + } + + private static void unparseFloor(SqlWriter writer, SqlCall call) { + SqlLiteral node = call.operand(1); + TimeUnitRange unit = node.getValueAs(TimeUnitRange.class); + + String format; + switch (unit) { + case YEAR: + format = "year"; + break; + case MONTH: + format = "month"; + break; + case WEEK: + format = "week"; + break; + case DAY: + format = "day"; + break; + case HOUR: + format = "hour"; + break; + case MINUTE: + format = "minute"; + break; + case SECOND: + format = "second"; + break; + case MILLISECOND: + format = "milliseconds"; + break; + case MICROSECOND: + format = "microseconds"; + break; + default: + throw new AssertionError("MYSQL does not support FLOOR for time unit: " Review Comment: Why MYSQL? ########## core/src/test/java/org/apache/calcite/rel/rel2sql/RelToSqlConverterTest.java: ########## @@ -5958,6 +5999,13 @@ private void checkLiteral2(String expression, String expected) { .ok(expected); } + @Test void testDuckDBDecimalPrecision() { + final String sql = "SELECT CAST(1.23 AS DECIMAL(38, 37))"; + final String expected = "SELECT 1.2300000000000000000000000000000000000"; Review Comment: I think this test would be more robust if the last digit was not 0 you are relying on the formatting to print zeros which are not significant, and this may not always be true -- This is an automated message from the Apache Git Service. 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