6 回答

TA貢獻1872條經驗 獲得超4個贊
一個student表student表包含三個字段的學生的ID(stu_id)學生姓名(stu_name),當然ID(les_id)
“CREATE TABLE [dbo的]。學生(/ stu_id。的uniqueidentifier] NOT NULL,
stu_name [數據類型為nvarchar](425)NOT NULL,
les_id [為uniqueidentifier] NOT NULL
)
第二個表中的課程課,有兩個字段,當然的ID(les_id)的和課程名稱(les_name)
CREATE TABLE [dbo的課(
les_id的uniqueidentifier] NOT NULL,
les_name [數據類型為nvarchar](425)NOT NULL
)< /第三個表,學生表的分數,三場場ID(les_id)的學生證(stu_id)和課程成績(les_score)
創建表[DBO]。分數(
les_id的uniqueidentifier] NULL,
stu_id的唯一標識符NOT NULL,
les_score [INT] NOT NULL
)

TA貢獻1874條經驗 獲得超12個贊
sqlserver:
--更改索引名: old_indName 改為 new_indName
1 | sp_rename 'tabName.old_indName' , 'new_indName' , 'INDEX' |
oracle的語法:
1 | ALTER INDEX employee_idx RENAME TO employee_index_Newname; |
Mysql:
For MySQL 5.7:
1 | ALTER TABLE tbl_name RENAME INDEX old_index_name TO new_index_name |
For MySQL older versions:
1 | ALTER TABLE tbl_name DROP INDEX old_index_name, ADD INDEX new_index_name (...) |

TA貢獻1752條經驗 獲得超4個贊
select * from course
select Sname,Sage from Student where sdept = '計算機系'
select * from sc where 70 <= grade and grade =>80
select Sname,Sage from Student where sdept = '計算機系' and Ssex='男'

TA貢獻1785條經驗 獲得超4個贊
1,select * from 2,select sname,sage from student where sdept = '計算機系' 3,select * from sc where 70 <= grade and grade =>80 寫不下去了,你就這樣的格式,select (要查詢的字段名) from (表名) where (查詢條件),,,,很簡單的,,
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