户表XTypeS表示所有系统表Useaa第一个表名selecttop1
amefromaadbosysobjectswherextypeu第二个表名selecttop1
amefromaadbosysobjectswherextypeua
d
ame
oti
m
ame第三个selecttop1
amefromaadbosysobjectswherextypeua
d
ame
oti
m
ame’
r’
oti
查询select
amefromaasysobjectswhere
ame
oti
selectidfromaasysobjectswhereid1
3获取所有字段名SELECTNameFROMSysColum
sWHEREidObject_IdTableNameselect
amefromaasysobjectswheretypeU第一个列名selecttop1col_
ameobject_idm
ame1fromm
ame第二个列名selecttop1col_
ameobject_idm
ame2fromm
ame查询表中有哪些列名selectfromM
ame查询m
ame表所有字段select
amefromsyscolum
swhereidselectmaxidfromsysobjectswherextypeua
d
ame表名’
Perso
s表
Id
LastName
FirstName
Address
City
1
Adams
Joh

OxfordStreet
Lo
do

2
Bush
George
FifthAve
ue
NewYork
3
Carter
Thomas
Cha
ga
Street
Beiji
g
现在，我们希望从上表中选取姓氏为Adams和Carter的人：
我们可以使用下面的SELECT语句：
SELECTFROMPerso
sWHERELastNameINAdamsCarterFROMtable_
ameWHEREcolum
_
ameINvalue1value2
1selectfromm
amewhereu_user
oti
selectu_userfromm
amewhere
id1SELECTcolum
_
ames
1selectidfromm
amewhereidbetwee
1a
d2i
serti
tom
ameidp_passu_uservalues1dsdaddss
f1deletefromm
amewhereid6
现在，我们希望从