| /* |
| * 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.type; |
| |
| import com.google.common.collect.ImmutableMap; |
| import com.google.common.collect.ImmutableSet; |
| |
| import org.checkerframework.checker.nullness.qual.Nullable; |
| |
| import java.util.HashSet; |
| import java.util.Map; |
| import java.util.Objects; |
| import java.util.Set; |
| |
| /** |
| * Rules that determine whether a type is castable from another type. |
| * |
| * <p>These rules specify the conversion matrix with explicit CAST. |
| * |
| * <p>The implicit type coercion matrix should be a sub-set of this explicit one. |
| * We do not define an implicit type coercion matrix, instead we have specific |
| * coercion rules for all kinds of SQL contexts which actually define the "matrix". |
| * |
| * <p>To add a new implementation to this class, follow |
| * these steps: |
| * |
| * <ol> |
| * <li>Initialize a {@link SqlTypeMappingRules.Builder} instance |
| * with default mappings of {@link SqlTypeCoercionRule#INSTANCE}.</li> |
| * <li>Modify the mappings with the Builder.</li> |
| * <li>Construct a new {@link SqlTypeCoercionRule} instance with method |
| * {@link #instance(Map)}.</li> |
| * <li>Set the {@link SqlTypeCoercionRule} instance into the |
| * {@link org.apache.calcite.sql.validate.SqlValidator}.</li> |
| * </ol> |
| * |
| * <p>The code snippet below illustrates how to implement a customized instance. |
| * |
| * <blockquote><pre>{@code |
| * // Initialize a Builder instance with the default mappings. |
| * Builder builder = SqlTypeMappingRules.builder(); |
| * builder.addAll(SqlTypeCoercionRules.instance().getTypeMapping()); |
| * |
| * // Do the tweak, for example, if we want to add a rule to allow |
| * // coerce BOOLEAN to TIMESTAMP. |
| * builder.add(SqlTypeName.TIMESTAMP, |
| * builder.copyValues(SqlTypeName.TIMESTAMP) |
| * .add(SqlTypeName.BOOLEAN).build()); |
| * |
| * // Initialize a SqlTypeCoercionRules with the new builder mappings. |
| * SqlTypeCoercionRules typeCoercionRules = SqlTypeCoercionRules.instance(builder.map); |
| * |
| * // Set the SqlTypeCoercionRules instance into the SqlValidator. |
| * SqlValidator.Config validatorConf ...; |
| * validatorConf.withTypeCoercionRules(typeCoercionRules); |
| * // Use this conf to initialize the SqlValidator. |
| * }</pre></blockquote> |
| */ |
| public class SqlTypeCoercionRule implements SqlTypeMappingRule { |
| //~ Static fields/initializers --------------------------------------------- |
| |
| private static final SqlTypeCoercionRule INSTANCE; |
| |
| private static final SqlTypeCoercionRule LENIENT_INSTANCE; |
| |
| public static final ThreadLocal<@Nullable SqlTypeCoercionRule> THREAD_PROVIDERS = |
| ThreadLocal.withInitial(() -> SqlTypeCoercionRule.INSTANCE); |
| |
| //~ Instance fields -------------------------------------------------------- |
| |
| private final Map<SqlTypeName, ImmutableSet<SqlTypeName>> map; |
| |
| //~ Constructors ----------------------------------------------------------- |
| |
| /** |
| * Creates a {@code SqlTypeCoercionRules} with specified type mappings {@code map}. |
| * |
| * <p>Make this constructor private intentionally, use {@link #instance()}. |
| * |
| * @param map The type mapping, for each map entry, the values types can be coerced to |
| * the key type |
| */ |
| private SqlTypeCoercionRule(Map<SqlTypeName, ImmutableSet<SqlTypeName>> map) { |
| this.map = ImmutableMap.copyOf(map); |
| } |
| |
| static { |
| // We use coerceRules when we're casting |
| final SqlTypeMappingRules.Builder coerceRules = SqlTypeMappingRules.builder(); |
| coerceRules.addAll(SqlTypeAssignmentRule.instance().getTypeMapping()); |
| |
| final Set<SqlTypeName> rule = new HashSet<>(); |
| |
| // Make numbers symmetrical, |
| // and make VARCHAR, CHAR, and TIMESTAMP castable to/from numbers |
| rule.add(SqlTypeName.TINYINT); |
| rule.add(SqlTypeName.SMALLINT); |
| rule.add(SqlTypeName.INTEGER); |
| rule.add(SqlTypeName.BIGINT); |
| rule.add(SqlTypeName.DECIMAL); |
| rule.add(SqlTypeName.FLOAT); |
| rule.add(SqlTypeName.REAL); |
| rule.add(SqlTypeName.DOUBLE); |
| |
| rule.add(SqlTypeName.CHAR); |
| rule.add(SqlTypeName.VARCHAR); |
| rule.add(SqlTypeName.TIMESTAMP); |
| rule.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE); |
| rule.add(SqlTypeName.TIMESTAMP_TZ); |
| |
| coerceRules.add(SqlTypeName.TINYINT, rule); |
| coerceRules.add(SqlTypeName.SMALLINT, rule); |
| coerceRules.add(SqlTypeName.INTEGER, rule); |
| coerceRules.add(SqlTypeName.BIGINT, rule); |
| coerceRules.add(SqlTypeName.FLOAT, rule); |
| coerceRules.add(SqlTypeName.REAL, rule); |
| coerceRules.add(SqlTypeName.DECIMAL, rule); |
| coerceRules.add(SqlTypeName.DOUBLE, rule); |
| coerceRules.add(SqlTypeName.CHAR, rule); |
| coerceRules.add(SqlTypeName.VARCHAR, rule); |
| |
| // Exact numeric types are castable from intervals |
| for (SqlTypeName exactType : SqlTypeName.EXACT_TYPES) { |
| coerceRules.add(exactType, |
| coerceRules.copyValues(exactType) |
| .addAll(SqlTypeName.INTERVAL_TYPES) |
| .build()); |
| } |
| |
| // Intervals are castable from exact numeric |
| for (SqlTypeName typeName : SqlTypeName.INTERVAL_TYPES) { |
| coerceRules.add(typeName, |
| coerceRules.copyValues(typeName) |
| .add(SqlTypeName.TINYINT) |
| .add(SqlTypeName.SMALLINT) |
| .add(SqlTypeName.INTEGER) |
| .add(SqlTypeName.BIGINT) |
| .add(SqlTypeName.DECIMAL) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .build()); |
| } |
| |
| // BINARY is castable from VARBINARY, CHARACTERS. |
| coerceRules.add(SqlTypeName.BINARY, |
| coerceRules.copyValues(SqlTypeName.BINARY) |
| .add(SqlTypeName.VARBINARY) |
| .addAll(SqlTypeName.CHAR_TYPES) |
| .build()); |
| |
| // VARBINARY is castable from BINARY, CHARACTERS. |
| coerceRules.add(SqlTypeName.VARBINARY, |
| coerceRules.copyValues(SqlTypeName.VARBINARY) |
| .add(SqlTypeName.BINARY) |
| .addAll(SqlTypeName.CHAR_TYPES) |
| .build()); |
| |
| // VARCHAR is castable from BOOLEAN, DATE, TIME, TIMESTAMP, numeric types, binary and |
| // intervals |
| coerceRules.add(SqlTypeName.VARCHAR, |
| coerceRules.copyValues(SqlTypeName.VARCHAR) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.BOOLEAN) |
| .add(SqlTypeName.DATE) |
| .add(SqlTypeName.TIME) |
| .add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .addAll(SqlTypeName.NUMERIC_TYPES) |
| .addAll(SqlTypeName.INTERVAL_TYPES) |
| .build()); |
| |
| // CHAR is castable from BOOLEAN, DATE, TIME, TIMESTAMP, numeric types, binary and |
| // intervals |
| coerceRules.add(SqlTypeName.CHAR, |
| coerceRules.copyValues(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .add(SqlTypeName.BOOLEAN) |
| .add(SqlTypeName.DATE) |
| .add(SqlTypeName.TIME) |
| .add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .addAll(SqlTypeName.NUMERIC_TYPES) |
| .addAll(SqlTypeName.INTERVAL_TYPES) |
| .build()); |
| |
| // BOOLEAN is castable from ... |
| coerceRules.add(SqlTypeName.BOOLEAN, |
| coerceRules.copyValues(SqlTypeName.BOOLEAN) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.NUMERIC_TYPES) |
| .build()); |
| |
| // DATE, TIME, and TIMESTAMP are castable from |
| // CHAR and VARCHAR. |
| |
| // DATE is castable from... |
| coerceRules.add(SqlTypeName.DATE, |
| coerceRules.copyValues(SqlTypeName.DATE) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .build()); |
| |
| // TIME is castable from... |
| coerceRules.add(SqlTypeName.TIME, |
| coerceRules.copyValues(SqlTypeName.TIME) |
| .add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .build()); |
| |
| // TIME WITH LOCAL TIME ZONE is castable from... |
| coerceRules.add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE, |
| coerceRules.copyValues(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.TIME) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .build()); |
| |
| // TIME WITH TIME ZONE is castable from... |
| coerceRules.add(SqlTypeName.TIME_TZ, |
| coerceRules.copyValues(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .build()); |
| |
| // TIMESTAMP is castable from... |
| coerceRules.add(SqlTypeName.TIMESTAMP, |
| coerceRules.copyValues(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .add(SqlTypeName.DATE) |
| .add(SqlTypeName.TIME) |
| .add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .addAll(SqlTypeName.NUMERIC_TYPES) |
| .build()); |
| |
| // TIMESTAMP WITH LOCAL TIME ZONE is castable from... |
| coerceRules.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE, |
| coerceRules.copyValues(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP_TZ) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.DATE) |
| .add(SqlTypeName.TIME) |
| .add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .addAll(SqlTypeName.NUMERIC_TYPES) |
| .build()); |
| |
| // TIMESTAMP WITH TIME ZONE is castable from... |
| coerceRules.add(SqlTypeName.TIMESTAMP_TZ, |
| coerceRules.copyValues(SqlTypeName.TIMESTAMP_TZ) |
| .add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIMESTAMP) |
| .add(SqlTypeName.DATE) |
| .add(SqlTypeName.TIME) |
| .add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE) |
| .add(SqlTypeName.TIME_TZ) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .addAll(SqlTypeName.BINARY_TYPES) |
| .addAll(SqlTypeName.NUMERIC_TYPES) |
| .build()); |
| |
| // GEOMETRY is castable from ... |
| coerceRules.add(SqlTypeName.GEOMETRY, |
| coerceRules.copyValues(SqlTypeName.GEOMETRY) |
| .addAll(SqlTypeName.CHAR_TYPES) |
| .build()); |
| |
| INSTANCE = new SqlTypeCoercionRule(coerceRules.map); |
| |
| // Lenient casting allowing casting between BOOLEAN and numbers. |
| rule.clear(); |
| |
| rule.add(SqlTypeName.TINYINT); |
| rule.add(SqlTypeName.SMALLINT); |
| rule.add(SqlTypeName.INTEGER); |
| rule.add(SqlTypeName.BIGINT); |
| rule.add(SqlTypeName.DECIMAL); |
| rule.add(SqlTypeName.FLOAT); |
| rule.add(SqlTypeName.REAL); |
| rule.add(SqlTypeName.DOUBLE); |
| |
| rule.add(SqlTypeName.CHAR); |
| rule.add(SqlTypeName.VARCHAR); |
| rule.add(SqlTypeName.BOOLEAN); |
| rule.add(SqlTypeName.TIMESTAMP); |
| rule.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE); |
| rule.add(SqlTypeName.TIMESTAMP_TZ); |
| |
| coerceRules.add(SqlTypeName.TINYINT, rule); |
| coerceRules.add(SqlTypeName.SMALLINT, rule); |
| coerceRules.add(SqlTypeName.INTEGER, rule); |
| coerceRules.add(SqlTypeName.BIGINT, rule); |
| |
| // Lenient casting allowing ARRAY to be casted from CHAR and VARCHAR. |
| coerceRules.add(SqlTypeName.ARRAY, |
| coerceRules.copyValues(SqlTypeName.ARRAY) |
| .add(SqlTypeName.CHAR) |
| .add(SqlTypeName.VARCHAR) |
| .build()); |
| |
| LENIENT_INSTANCE = new SqlTypeCoercionRule(coerceRules.map); |
| } |
| |
| //~ Methods ---------------------------------------------------------------- |
| |
| /** Returns an instance. */ |
| public static SqlTypeCoercionRule instance() { |
| return Objects.requireNonNull(THREAD_PROVIDERS.get(), "threadProviders"); |
| } |
| |
| /** Returns an instance that allows more lenient type coercion. */ |
| public static SqlTypeCoercionRule lenientInstance() { |
| return LENIENT_INSTANCE; |
| } |
| |
| /** Returns an instance with specified type mappings. */ |
| public static SqlTypeCoercionRule instance( |
| Map<SqlTypeName, ImmutableSet<SqlTypeName>> map) { |
| return new SqlTypeCoercionRule(map); |
| } |
| |
| @Override public Map<SqlTypeName, ImmutableSet<SqlTypeName>> getTypeMapping() { |
| return this.map; |
| } |
| } |