springboot动态建立表修改表结构删除表工具

Posted 2021-11-23 洛阳泰山

代码如下（以postgressql为列子）

基于JdbcTemplate 实现

import lombok.AllArgsConstructor;
import org.springblade.core.tool.utils.StringUtil;
import org.springblade.gis.constant.AppConst;
import org.springblade.gis.modules.feature.attribute.entity.AttributeItemEntity;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.util.*;

@Service
@AllArgsConstructor
public class DbStructureService {

    private final JdbcTemplate jdbcTemplate;



    public boolean createTable(Long id, List<AttributeItemEntity> columns){
            return createTable(AppConst.tablePrefix+id,columns);
    }

    public boolean dropTables(List<Long> ids){
        List<String> tableNames=new ArrayList<>();
        ids.forEach(id->{
            tableNames.add(AppConst.tablePrefix+id);
        });
        return dropTable(tableNames);
    }

    public  boolean addColumns(Long id,List<AttributeItemEntity> columns){
        return addColumns(AppConst.tablePrefix+id,columns);
    }

    public  boolean updateColumns(Long id,List<AttributeItemEntity> columns,Map<Long,String> oldColumnMap){
        return updateColumns(AppConst.tablePrefix+id,columns,oldColumnMap);
    }

    public  boolean dropColumns(Long id,List<AttributeItemEntity> columns){
        return dropColumns(AppConst.tablePrefix+id,columns);
    }

    private String columnType(String type,Integer length){
        if("varchar".equals(type)){
            if(Objects.isNull(length)||length==0){
                length=255;
            }
            return type+"("+length+")";
        }
        return type;
    }

    private   boolean createTable(String tableName,List<AttributeItemEntity> columns){
        StringBuffer sb = new StringBuffer();
        sb.append("CREATE TABLE IF NOT EXISTS \\"public\\".\\""+tableName+"\\" (\\n");
        sb.append("id int8 NOT NULL,\\n");
        columns.forEach(e->{
            sb.append(e.getName() + " "+columnType(e.getType(),e.getLength())+" "+isNullSql(e.getEnableNull())+" "+isDefaultSql(e.getDefaultValue())+",\\n");
        });
        sb.append("create_time timestamp(6) NOT NULL DEFAULT CURRENT_TIMESTAMP\\n");
        sb.append(");\\n");
        sb.append("COMMENT ON COLUMN \\"public\\".\\""+tableName+"\\".\\"id\\" IS '主键';\\n");
        columns.forEach(e->{
            sb.append("COMMENT ON COLUMN \\"public\\".\\""+tableName+"\\".\\""+e.getName()+"\\" IS '"+e.getAlias()+"';\\n");
        });
        sb.append("COMMENT ON COLUMN \\"public\\".\\""+tableName+"\\".\\"create_time\\" IS '创建时间';\\n");
        sb.append("ALTER TABLE \\"public\\".\\""+tableName+"\\" ADD CONSTRAINT \\""+tableName+"_pkey\\" PRIMARY KEY (\\"id\\");");
        return  execute(sb);
    }

    private  boolean addColumns(String tableName,List<AttributeItemEntity> columns){
        StringBuffer sb = new StringBuffer();
            columns.forEach(e->{
                sb.append("ALTER TABLE \\"public\\".\\""+tableName+"\\"  ADD COLUMN \\""+e.getName() + "\\" "+columnType(e.getType(),e.getLength())+" "+isNullSql(e.getEnableNull())+" "+isDefaultSql(e.getDefaultValue())+";\\n");
                sb.append("COMMENT ON COLUMN \\"public\\".\\""+tableName+"\\".\\""+e.getName()+"\\" IS '"+e.getAlias()+"';\\n");
            });
            return execute(sb);
    }

    private  boolean updateColumns(String tableName,List<AttributeItemEntity> columns,Map<Long,String> oldColumnMap){
        StringBuffer sb = new StringBuffer();
        columns.forEach(e->{
            String oldName=oldColumnMap.get(e.getId());
            if(oldName!=null&&!oldName.equals(e.getName())){
             sb.append("ALTER TABLE \\"public\\".\\""+tableName+"\\"  RENAME COLUMN \\""+oldName + "\\" TO \\""+e.getName()+"\\";\\n");
            }
            sb.append("COMMENT ON COLUMN \\"public\\".\\""+tableName+"\\".\\""+e.getName()+"\\" IS '"+e.getAlias()+"';\\n");
        });
        return execute(sb);
    }

    private  boolean dropColumns(String tableName,List<AttributeItemEntity> columns){
        StringBuffer sb = new StringBuffer();
        columns.forEach(e->{
            sb.append("ALTER TABLE \\"public\\".\\""+tableName+"\\"  DROP COLUMN \\""+e.getName()+"\\";\\n");
        });
        return execute(sb);
    }


    private  boolean dropTable(List<String> tableNames){
        StringBuffer sb = new StringBuffer();
        tableNames.forEach(tableName->{
            sb.append("DROP TABLE IF EXISTS \\"public\\".\\""+tableName+"\\";");
        });
        return  execute(sb);
    }

    //获取所有表名称
    public List<String> tableNames() {
        List<String> tableNames= new ArrayList<>();
        try {
            Connection getConnection=jdbcTemplate.getDataSource().getConnection();
            DatabaseMetaData metaData = getConnection.getMetaData();
            ResultSet rs = metaData.getTables(getConnection.getCatalog(), null, null, new String[] { "TABLE" });
            while (rs.next()) {
                String tableName=rs.getString("TABLE_NAME");
                tableNames.add(tableName);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return tableNames;
    }


    private  boolean execute(StringBuffer sb){
        try {
            jdbcTemplate.execute(sb.toString());
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    private String isNullSql(Boolean boo){
        if(boo){
            return "NOT NULL";
        }
        return "";
    }

    private String isDefaultSql(Object obj){
        if(Objects.nonNull(obj)){
            if(obj instanceof String){
                if(StringUtil.isEmpty(obj)){
                    return "";
                }
            }
            return "DEFAULT "+obj;
        }
        return "";
    }



}