提交 b59c5144 authored 作者: Thomas Mueller's avatar Thomas Mueller

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上级 ebd36602
WITH DirectReports (ManagerID, EmployeeID, Title, DeptID, Level)
AS
(
-- Anchor member definition
SELECT e.ManagerID, e.EmployeeID, e.Title, edh.DepartmentID,
0 AS Level
FROM Employee AS e
INNER JOIN EmployeeDepartmentHistory AS edh
ON e.EmployeeID = edh.EmployeeID AND edh.EndDate IS NULL
WHERE ManagerID IS NULL
UNION ALL
-- Recursive member definition
SELECT e.ManagerID, e.EmployeeID, e.Title, edh.DepartmentID,
Level + 1
FROM Employee AS e
INNER JOIN EmployeeDepartmentHistory AS edh
ON e.EmployeeID = edh.EmployeeID AND edh.EndDate IS NULL
INNER JOIN DirectReports AS d
ON e.ManagerID = d.EmployeeID
)
-- Statement that executes the CTE
SELECT ManagerID, EmployeeID, Title, Level
FROM DirectReports
INNER JOIN Department AS dp
ON DirectReports.DeptID = dp.DepartmentID
WHERE dp.GroupName = N'Research and Development' OR Level = 0;
GO
DROP VIEW IF EXISTS TEST_REC;
DROP VIEW IF EXISTS TEST_2;
DROP TABLE IF EXISTS TEST;
CREATE TABLE TEST(ID INT PRIMARY KEY, PARENT INT, NAME VARCHAR(255));
INSERT INTO TEST VALUES(1, NULL, 'Root');
INSERT INTO TEST VALUES(2, 1, 'Plant');
INSERT INTO TEST VALUES(3, 1, 'Animal');
INSERT INTO TEST VALUES(4, 2, 'Tree');
INSERT INTO TEST VALUES(5, 2, 'Flower');
INSERT INTO TEST VALUES(6, 3, 'Elephant');
INSERT INTO TEST VALUES(7, 3, 'Dog');
CREATE FORCE VIEW TEST_2(ID, PARENT, NAME) AS SELECT ID, PARENT, NAME FROM TEST_REC;
CREATE FORCE VIEW TEST_REC(ID, PARENT, NAME) AS
SELECT ID, PARENT, NAME FROM TEST T
WHERE PARENT IS NULL
UNION ALL
SELECT T.ID, T.PARENT, T.NAME
FROM TEST T, TEST_2 R
WHERE T.PARENT=R.ID;
SELECT * FROM TEST_REC;
------------
DROP VIEW IF EXISTS TEST_REC;
DROP VIEW IF EXISTS TEST_2;
DROP TABLE IF EXISTS TEST;
CREATE TABLE TEST(ID INT PRIMARY KEY, PARENT INT, NAME VARCHAR(255));
INSERT INTO TEST VALUES(1, NULL, 'Root');
INSERT INTO TEST VALUES(2, 1, 'Plant');
INSERT INTO TEST VALUES(3, 1, 'Animal');
INSERT INTO TEST VALUES(4, 2, 'Tree');
INSERT INTO TEST VALUES(5, 2, 'Flower');
INSERT INTO TEST VALUES(6, 3, 'Elephant');
INSERT INTO TEST VALUES(7, 3, 'Dog');
CREATE VIEW RECURSIVE TEST_REC(ID, PARENT, NAME) AS
SELECT ID, PARENT, NAME FROM TEST T
WHERE PARENT IS NULL
UNION ALL
SELECT T.ID, T.PARENT, T.NAME
FROM TEST T, TEST_REC R
WHERE T.PARENT=R.ID;
SELECT * FROM TEST_REC;
----------------
CREATE LOCAL TEMPORARY TABLE test (family_name VARCHAR_IGNORECASE(63) NOT NULL);
INSERT INTO test VALUES('Smith');
INSERT INTO test VALUES('de Smith');
INSERT INTO test VALUES('el Smith');
INSERT INTO test VALUES('von Smith');
SELECT * FROM test WHERE family_name IN ('de Smith', 'Smith');
-- okay IN(...) with TABLE_SCAN
SELECT * FROM test WHERE family_name BETWEEN 'd' AND 'T';
-- okay, ignorecase honoured
SELECT * FROM test WHERE family_name BETWEEN 'D' AND 'T';
-- okay, ignorecase honoured
CREATE INDEX family_name ON test(family_name);
SELECT * FROM test WHERE family_name IN ('de Smith', 'Smith');
-- OOPS, the comparison's operands are sorted incorrectly for ignorecase!
EXPLAIN SELECT * FROM test WHERE family_name IN ('de Smith', 'Smith');
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