SQL Server递归查询

Posted 2023-02-28

本示例仅适用于SQL Server 2005及以上版本

1.语法结构

语法结构基本上与PostgreSql的一致，不同之处在于with后面直接跟临时表表名，且内部使用"union all"连接。

with 临时表名称 as (
    A.初始条件语句(非递归部分)
    
    union all
    
    B.递归部分语句
) [SELECT | INSERT | UPDATE | DELETE]

1.1 说明

1. 前半部分A为初始条件语句，后半部分B为要进行的递归语句
2. 先执行A语句，然后将A语句的结果作为B语句的条件，使用union all进行连接

2.示例

2.1 表结构

创建表信息

-- ----------------------------
-- Table structure for rbac_menu
-- ----------------------------
IF EXISTS (SELECT * FROM sys.all_objects WHERE object_id = OBJECT_ID(N[rbac_menu]) AND type IN (U))
  DROP TABLE [rbac_menu]
GO

CREATE TABLE [rbac_menu] (
  [id] bigint  NOT NULL,
  [pid] bigint  NULL,
  [menu_name] nvarchar(255) COLLATE Chinese_PRC_CI_AS  NULL
)
GO

ALTER TABLE [rbac_menu] SET (LOCK_ESCALATION = TABLE)
GO

EXEC sp_addextendedproperty
MS_Description, NID,
SCHEMA, Ndbo,
TABLE, Nrbac_menu,
COLUMN, Nid
GO

EXEC sp_addextendedproperty
MS_Description, N父ID,
SCHEMA, Ndbo,
TABLE, Nrbac_menu,
COLUMN, Npid
GO

EXEC sp_addextendedproperty
MS_Description, N菜单名称,
SCHEMA, Ndbo,
TABLE, Nrbac_menu,
COLUMN, Nmenu_name
GO

-- ----------------------------
-- Records of rbac_menu
-- ----------------------------
INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N100101, N1001, N权限管理)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N10010101, N100101, N菜单管理)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N10010102, N100101, N用户管理)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N10010103, N100101, N角色管理)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N1001010101, N10010101, N设置角色)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N1001010102, N10010101, N设置用户)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N1001010301, N10010103, N查看)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N1001010302, N10010103, N新增)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N1001010303, N10010103, N修改)
GO

INSERT INTO [rbac_menu] ([id], [pid], [menu_name]) VALUES (N1001010304, N10010103, N删除)
GO

-- ----------------------------
-- Primary Key structure for table rbac_menu
-- ----------------------------
ALTER TABLE [rbac_menu] ADD CONSTRAINT [rbac_menu_pkey] PRIMARY KEY CLUSTERED ([id])
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON)  
ON [PRIMARY]
GO

查询表数据

select * from rbac_menu;

查询结果

2.2 获取所有子节点信息

with temp_table as (
    -- 初始语句,仅执行一次
    select "id", pid, "menu_name" from rbac_menu where pid = 1001
    
    -- 使用union连接结果集(去重,不去重请使用"union all")
    union all
    
    -- 递归语句
    select a."id", a.pid, a."menu_name" from rbac_menu a,temp_table b where a.pid = b."id"
)
select * from temp_table order by pid, "id";

查询结果

2.3 获取所有子节点信息(控制递归层数)

with temp_table as (
    -- 初始语句,仅执行一次,设置一个变量 number=1
    select
        1 number, "id", pid, "menu_name"
    from
        rbac_menu
    where
        pid = 1001
    
    -- 使用union连接结果集(去重,不去重请使用"union all")
    union all
    
    -- 递归语句,执行number次,控制number,即可控制递归的层次
    select
        (number+1) as n, a."id", a.pid, a."menu_name"
    from
        rbac_menu a,temp_table b
    where
        a.pid = b."id"
        and number < 2  -- 递归2层
) select * from temp_table
order by pid, "id";

查询结果

2.4 获取所有父节点信息

with temp_table as (
    select "id", pid, "menu_name" from rbac_menu where "id" = 1001010302
        
    union all
        
    select a."id", a.pid, a."menu_name" from rbac_menu a,temp_table b where a.id = b.pid
)
select * from temp_table order by pid desc, "id" desc;

查询结果

2.5 任意节点获取所有父节点及子节点信息(包括自身)

with temp_table as (
    select "id", pid, "menu_name" from rbac_menu where "id" = 10010103
    union all
    select a."id", a.pid, a."menu_name" from rbac_menu a,temp_table b   where a."id" = b.pid
), temp_table_b as (
    select "id", pid, "menu_name" from rbac_menu where pid  = 10010103
    union all        
    select a."id", a.pid, a."menu_name" from rbac_menu a,temp_table_b b where a.pid  = b."id"
) 
select * from temp_table
union
select * from temp_table_b order by pid, "id";

查询结果