com.hazelcast.org.apache.calcite.sql.type.SqlTypeCoercionRule Maven / Gradle / Ivy
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* 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 com.hazelcast.com.liance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.com.hazelcast.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 com.hazelcast.org.apache.calcite.sql.type;
import com.hazelcast.com.google.com.hazelcast.com.on.collect.ImmutableMap;
import com.hazelcast.com.google.com.hazelcast.com.on.collect.ImmutableSet;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
* Rules that determine whether a type is castable from another type.
*
* These rules specify the conversion matrix with explicit CAST.
*
*
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".
*
*
To add a new implementation to this class, follow
* these steps:
*
*
* - Initialize a {@link SqlTypeMappingRules.Builder} instance
* with default mappings of {@link SqlTypeCoercionRule#INSTANCE}.
* - Modify the mappings with the Builder.
* - Construct a new {@link SqlTypeCoercionRule} instance with method
* {@link #instance(Map)}.
* - Set the {@link SqlTypeCoercionRule} instance into the
* {@link com.hazelcast.org.apache.calcite.sql.validate.SqlValidator}.
*
*
* The code snippet below illustrates how to implement a customized instance.
*
*
* // 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.
*
*/
public class SqlTypeCoercionRule implements SqlTypeMappingRule {
//~ Static fields/initializers ---------------------------------------------
private static final SqlTypeCoercionRule INSTANCE;
public static final ThreadLocal THREAD_PROVIDERS =
ThreadLocal.withInitial(() -> SqlTypeCoercionRule.INSTANCE);
//~ Instance fields --------------------------------------------------------
private final Map> map;
//~ Constructors -----------------------------------------------------------
/**
* Creates a {@code SqlTypeCoercionRules} with specified type mappings {@code map}.
*
* 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> 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 rule = new HashSet<>();
// Make numbers symmetrical,
// and make VARCHAR, CHAR, BOOLEAN 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.BOOLEAN);
rule.add(SqlTypeName.TIMESTAMP);
rule.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE);
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.TIMESTAMP)
.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.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.TIMESTAMP)
.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.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.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.TIMESTAMP)
.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.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)
.add(SqlTypeName.TIMESTAMP)
.add(SqlTypeName.TIMESTAMP_WITH_LOCAL_TIME_ZONE)
.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.DATE)
.add(SqlTypeName.TIME)
.add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE)
.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)
.add(SqlTypeName.DATE)
.add(SqlTypeName.TIME)
.add(SqlTypeName.TIME_WITH_LOCAL_TIME_ZONE)
.add(SqlTypeName.CHAR)
.add(SqlTypeName.VARCHAR)
.addAll(SqlTypeName.BINARY_TYPES)
.addAll(SqlTypeName.NUMERIC_TYPES)
.build());
INSTANCE = new SqlTypeCoercionRule(coerceRules.map);
}
//~ Methods ----------------------------------------------------------------
/** Returns an instance. */
public static SqlTypeCoercionRule instance() {
return THREAD_PROVIDERS.get();
}
/** Returns an instance with specified type mappings. */
public static SqlTypeCoercionRule instance(
Map> map) {
return new SqlTypeCoercionRule(map);
}
@Override public Map> getTypeMapping() {
return this.map;
}
}