content: /*
   * 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.Casing;
  import org.apache.calcite.config.NullCollation;
  import org.apache.calcite.sql.SqlCall;
  import org.apache.calcite.sql.SqlDialect;
  import org.apache.calcite.sql.SqlNode;
  import org.apache.calcite.sql.SqlWriter;
  import org.apache.calcite.sql.fun.SqlStdOperatorTable;
  import org.apache.calcite.util.RelToSqlConverterUtil;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /**
   * A <code>SqlDialect</code> implementation for the Trino database.
   */
  public class TrinoSqlDialect extends PrestoSqlDialect {
    public static final Context DEFAULT_CONTEXT = SqlDialect.EMPTY_CONTEXT
        .withDatabaseProduct(DatabaseProduct.TRINO)
        .withIdentifierQuoteString("\"")
        .withUnquotedCasing(Casing.UNCHANGED)
        .withNullCollation(NullCollation.LAST);
  
    public static final SqlDialect DEFAULT = new TrinoSqlDialect(DEFAULT_CONTEXT);
  
    /**
     * Creates a TrinoSqlDialect.
     */
    public TrinoSqlDialect(Context context) {
      super(context);
    }
  
    @Override public void unparseOffsetFetch(SqlWriter writer, @Nullable SqlNode offset,
        @Nullable SqlNode fetch) {
      unparseFetchUsingAnsi(writer, offset, fetch);
    }
  
    @Override public void unparseCall(SqlWriter writer, SqlCall call,
        int leftPrec, int rightPrec) {
      if (call.getOperator() == SqlStdOperatorTable.SUBSTRING) {
        RelToSqlConverterUtil.specialOperatorByName("SUBSTRING")
            .unparse(writer, call, 0, 0);
      } else {
        super.unparseCall(writer, call, leftPrec, rightPrec);
      }
    }
  
  }
  