tk.mybatis.mapper.provider.SaveProvider Maven / Gradle / Ivy

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package tk.mybatis.mapper.provider;

import org.apache.ibatis.mapping.MappedStatement;
import tk.mybatis.mapper.MapperException;
import tk.mybatis.mapper.entity.EntityColumn;
import tk.mybatis.mapper.mapperhelper.*;

import java.lang.reflect.Field;
import java.util.Set;

/**
 * 保存实现类
 * Created by YangBin on 2020/5/12
 * Copyright (c) 2020 杨斌 All rights reserved.
 */
public class SaveProvider extends MapperTemplate {


    public SaveProvider(Class mapperClass, MapperHelper mapperHelper) {
        super(mapperClass, mapperHelper);
    }

    /**
     * 保存策略: 如果主键不为空则更新记录, 如果没有主键或者主键为空,则插入.
     * @param ms
     * @return
     */
    public String save(MappedStatement ms){

        Class entityClass = getEntityClass(ms);
        Field[] fields = entityClass.getFields();
        StringBuilder sql = new StringBuilder();

        Set columnList = EntityHelper.getPKColumns(entityClass);
        if (columnList.size() == 1) {
            EntityColumn column = (EntityColumn)columnList.iterator().next();
            String id = column.getColumn();
            sql.append("");
            sql.append("");
            sql.append(updateByPrimaryKey(ms));
            sql.append("");
            sql.append("");
            sql.append(insert(ms));
            sql.append("");
            sql.append("");
            return sql.toString();
        }
        return insert(ms);
    }

    /**
     * 通过主键更新全部字段
     *
     * @param ms
     */
    public String updateByPrimaryKey(MappedStatement ms) {
        Class entityClass = getEntityClass(ms);
        StringBuilder sql = new StringBuilder();
        sql.append(SqlHelper.updateTable(entityClass, tableName(entityClass)));
        sql.append(SqlHelper.updateSetColumns(entityClass, null, false, false));
        sql.append(SqlHelper.wherePKColumns(entityClass, true));
        return sql.toString();
    }

    public String insert(MappedStatement ms) {
        Class entityClass = getEntityClass(ms);
        StringBuilder sql = new StringBuilder();
        //获取全部列
        Set columnList = EntityHelper.getColumns(entityClass);
        processKey(sql, entityClass, ms, columnList);
        sql.append(SqlHelper.insertIntoTable(entityClass, tableName(entityClass)));
        sql.append(SqlHelper.insertColumns(entityClass, false, false, false));
        sql.append("");
        for (EntityColumn column : columnList) {
            if (!column.isInsertable()) {
                continue;
            }
            //优先使用传入的属性值,当原属性property!=null时，用原属性
            //自增的情况下,如果默认有值,就会备份到property_cache中,所以这里需要先判断备份的值是否存在
            if (column.isIdentity()) {
                sql.append(SqlHelper.getIfCacheNotNull(column, column.getColumnHolder(null, "_cache", ",")));
            } else {
                //其他情况值仍然存在原property中
                sql.append(SqlHelper.getIfNotNull(column, column.getColumnHolder(null, null, ","), isNotEmpty()));
            }
            //当属性为null时，如果存在主键策略，会自动获取值，如果不存在，则使用null
            if (column.isIdentity()) {
                sql.append(SqlHelper.getIfCacheIsNull(column, column.getColumnHolder() + ","));
            } else {
                //当null的时候，如果不指定jdbcType，oracle可能会报异常，指定VARCHAR不影响其他
                sql.append(SqlHelper.getIfIsNull(column, column.getColumnHolder(null, null, ","), isNotEmpty()));
            }
        }
        sql.append("");
        return sql.toString();
    }

    private void processKey(StringBuilder sql, Class entityClass, MappedStatement ms, Set columnList){
        //Identity列只能有一个
        Boolean hasIdentityKey = false;
        //先处理cache或bind节点
        for (EntityColumn column : columnList) {
            if (column.isIdentity()) {
                //这种情况下,如果原先的字段有值,需要先缓存起来,否则就一定会使用自动增长
                //这是一个bind节点
                sql.append(SqlHelper.getBindCache(column));
                //如果是Identity列，就需要插入selectKey
                //如果已经存在Identity列，抛出异常
                if (hasIdentityKey) {
                    //jdbc类型只需要添加一次
                    if (column.getGenerator() != null && column.getGenerator().equals("JDBC")) {
                        continue;
                    }
                    throw new MapperException(ms.getId() + "对应的实体类" + entityClass.getName() + "中包含多个MySql的自动增长列,最多只能有一个!");
                }
                //插入selectKey
                SelectKeyHelper.newSelectKeyMappedStatement(ms, column, entityClass, isBEFORE(), getIDENTITY(column));
                hasIdentityKey = true;
            } else if(column.getGenIdClass() != null){
                sql.append("");
            }

        }
    }
}