All Downloads are FREE. Search and download functionalities are using the official Maven repository.

io.github.matteobertozzi.easerinsights.jdbc.sql.impl.DialectMySql Maven / Gradle / Ivy

The newest version!
/*
 * 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 io.github.matteobertozzi.easerinsights.jdbc.sql.impl;

import java.util.ArrayList;

import io.github.matteobertozzi.easerinsights.jdbc.sql.Sql;
import io.github.matteobertozzi.easerinsights.jdbc.sql.SqlSelectQuery;
import io.github.matteobertozzi.easerinsights.jdbc.sql.SqlTableSchema;
import io.github.matteobertozzi.easerinsights.jdbc.sql.SqlTableSchema.SqlField;

public class DialectMySql implements Sql {
  public static final DialectMySql INSTANCE = new DialectMySql();

  private DialectMySql() {
    // no-op
  }

  @Override
  public FromTableQueryBuilder fromTable(final SqlTableSchema table, final SqlField... fields) {
    return new MySqlFromTableQueryBuilder(table, fields);
  }

  private static StringBuilder addTableName(final StringBuilder sql, final SqlTableSchema table) {
    return sql.append('`').append(table.tableName()).append('`');
  }

  private static StringBuilder addFieldName(final StringBuilder sql, final SqlField field) {
    return sql.append('`').append(field.name()).append('`');
  }

  private static final class MySqlFromTableQueryBuilder implements FromTableQueryBuilder {
    private final ArrayList bindParams = new ArrayList<>();
    private final StringBuilder sqlBuilder = new StringBuilder();
    private final SqlField[] fields;

    public MySqlFromTableQueryBuilder(final SqlTableSchema table, final SqlField[] fields) {
      this.fields = fields;
      sqlBuilder.append("SELECT ");
      addFieldName(sqlBuilder, fields[0]);
      for (int i = 1; i < fields.length; ++i) {
        sqlBuilder.append(',');
        addFieldName(sqlBuilder, fields[i]);
      }
      sqlBuilder.append(" FROM ");
      addTableName(sqlBuilder, table);
    }

    @Override
    public SqlExprImpl where() {
      sqlBuilder.append(" WHERE ");
      return new SqlExprImpl<>(this, sqlBuilder, bindParams, DialectMySql::addFieldName);
    }

    @Override
    public FromTableQueryBuilder limit(final long n) {
      sqlBuilder.append(" LIMIT ").append(n);
      return this;
    }

    @Override
    public SqlSelectQuery build() {
      return new SqlSelectQuery(fields, sqlBuilder.toString(), bindParams);
    }
  }
}