Question

我的问题与this question有关。我想切换一个表的两个id，它们被定义为主键。

但遗憾的是，我想要切换id的表已经创建，主键约束未设置为deferrable。

我尝试使用以下语句将其设置为可延迟： alter table table_name alter constraint primary_key_name_pkey deferrable;

得到一个错误： constraint "primary_key_name_pkey" of relation "table_name" is not a foreign key constraint

有没有办法在创建后将主键约束设置为可推迟？

感谢您的帮助。

Answer 1

如PostgreSQL源代码中所述：

package controllers;

import models.Sysuser;
import models.DataI;
import models.DataII;
import play.mvc.Controller;
import play.mvc.Result;
import play.mvc.Security;
import views.html.sitemap.index;

import javax.inject.*;
import java.util.concurrent.CompletionStage;
import play.libs.concurrent.HttpExecutionContext;
import static java.util.concurrent.CompletableFuture.supplyAsync;

import io.ebean.*;
import play.Logger;
import java.util.List;
import play.libs.Json;
import java.util.*;
import java.util.stream.*;

@Security.Authenticated(Secured.class)
public class SiteMap extends Controller {

    private final HttpExecutionContext httpExecutionContext;
    private static final Logger.ALogger logger = Logger.of(SiteMap.class);

    @Inject
    public SiteMap(HttpExecutionContext httpExecutionContext) {
        this.httpExecutionContext = httpExecutionContext;
    }   



    public CompletionStage<Result> index() {
      return supplyAsync(() -> {          
        return ok(views.html.sitemap.index.render(Sysuser.findByUserName(request().username()), QueryI(), QueryII() ));
        }, httpExecutionContext.current());
    }


    /**
     * Custom Query 1
     */ 
    public List<DataI> QueryI() {
                final String sql =  "SELECT sysuser_id, role_id "
                                   +"from sysuser_role "
                                   +"where sysuser_id = '1' "
                                   +"and role_id in ('1','2','3','4','5') ";
                final RawSql rawSql = RawSqlBuilder.parse(sql).create();                
                Query<DataI> query = Ebean.find(DataI.class);  
                query.setRawSql(rawSql);
                List<DataI> L = query.findList();
    return(L);
    }


    /**
     * Custom Query 2
     */ 
    public List<DataII> QueryII() {
                final String sql =  "SELECT sysuser.name, sysuser.active, department.description "
                                   +"from sysuser "
                                   +"left join department on department.id = sysuser.department_id "
                                   +"where sysuser.id = '2' ";
                final RawSql rawSql = RawSqlBuilder.parse(sql).create();                
                Query<DataII> query = Ebean.find(DataII.class);  
                query.setRawSql(rawSql);
                List<DataII> L = query.findList();
    return(L);
    }   





}

来源：https://github.com/postgres/postgres/blob/master/src/backend/commands/tablecmds.c#L9557

因此，即使使用Pg12，也是不可能的。

是否可以将主键设置为DEFERRABLE？

1 个答案: