org.dromara.hutool.db.dialect.impl.MysqlDialect Maven / Gradle / Ivy
/*
* Copyright (c) 2013-2024 Hutool Team and hutool.cn
*
* Licensed 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.dromara.hutool.db.dialect.impl;
import org.dromara.hutool.core.text.StrUtil;
import org.dromara.hutool.db.Entity;
import org.dromara.hutool.db.Page;
import org.dromara.hutool.db.sql.StatementUtil;
import org.dromara.hutool.db.config.DbConfig;
import org.dromara.hutool.db.dialect.DialectName;
import org.dromara.hutool.db.sql.QuoteWrapper;
import org.dromara.hutool.db.sql.SqlBuilder;
import java.sql.Connection;
import java.sql.PreparedStatement;
/**
* MySQL方言
*
* @author loolly
*/
public class MysqlDialect extends AnsiSqlDialect {
private static final long serialVersionUID = -3734718212043823636L;
/**
* 构造
*
* @param dbConfig 数据库配置
*/
public MysqlDialect(final DbConfig dbConfig) {
super(dbConfig);
quoteWrapper = new QuoteWrapper('`');
}
@Override
protected SqlBuilder wrapPageSql(final SqlBuilder find, final Page page) {
return find.append(" LIMIT ").append(page.getBeginIndex()).append(", ").append(page.getPageSize());
}
@Override
public String dialectName() {
return DialectName.MYSQL.toString();
}
/**
* 构建用于upsert的{@link PreparedStatement}
* MySQL通过主键方式实现Upsert,故keys无效,生成SQL语法为:
*
* INSERT INTO demo(a,b,c) values(?, ?, ?) ON DUPLICATE KEY UPDATE a=values(a), b=values(b), c=values(c);
*
*
* @param conn 数据库连接对象
* @param entity 数据实体类(包含表名)
* @param keys 此参数无效
* @return PreparedStatement
* @since 5.7.20
*/
@Override
public PreparedStatement psForUpsert(final Connection conn, final Entity entity, final String... keys) {
SqlBuilder.validateEntity(entity);
final SqlBuilder builder = SqlBuilder.of(quoteWrapper);
final StringBuilder fieldsPart = new StringBuilder();
final StringBuilder placeHolder = new StringBuilder();
final StringBuilder updateHolder = new StringBuilder();
// 构建字段部分和参数占位符部分
entity.forEach((field, value) -> {
if (StrUtil.isNotBlank(field)) {
if (fieldsPart.length() > 0) {
// 非第一个参数,追加逗号
fieldsPart.append(", ");
placeHolder.append(", ");
updateHolder.append(", ");
}
field = (null != quoteWrapper) ? quoteWrapper.wrap(field) : field;
fieldsPart.append(field);
updateHolder.append(field).append("=values(").append(field).append(")");
placeHolder.append("?");
builder.addParams(value);
}
});
String tableName = entity.getTableName();
if (null != this.quoteWrapper) {
tableName = this.quoteWrapper.wrap(tableName);
}
builder.append("INSERT INTO ").append(tableName)
// 字段列表
.append(" (").append(fieldsPart)
// 更新值列表
.append(") VALUES (").append(placeHolder)
// 主键冲突后的更新操作
.append(") ON DUPLICATE KEY UPDATE ").append(updateHolder);
return StatementUtil.prepareStatement(false, this.dbConfig, conn, builder.build(), builder.getParamValueArray());
}
}