根据一个表更新另外一表的数据

根据一个表的数据来更新另外一表的数据：



Oralce和DB2：



UPDATE A
SET (A1, A2, A3) = (SELECT B1, B2, B3 FROM B WHERE A.ID = B.ID)



UPDATE A
SET (A1, A2, A3) = (SELECT B1, B2, B3 FROM B WHERE A.ID = B.ID)
WHERE ID IN (SELECT B.ID FROM B WHERE A.ID = B.ID)



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MS SQL Server：



UPDATE A
SET A1 = B1, A2 = B2, A3 = B3
FROM A LEFT JOIN B ON A.ID = B.ID

UPDATE A
SET A1 = B1, A2 = B2, A3 = B3
FROM A, B WHERE A.ID = B.ID







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另今天写一脚本，没技术含量，已改进，记录一笔：



#------------------------------------
# GetDate for each day.
#------------------------------------

k=0

while [ $k -lt 12 ]
do

i=0
let k=$k+1

case $k in
1|3|5|7|8|10|12)
j=31;;
4|6|9|11)
j=30 ;;
2)
j=28;;
*)
echo fuck！;;
esac

if [ $k -lt 10 ]; then
k=0$k
fi

while [ $i -lt $j ]
do

let i=$i+1

if [ $i -lt 10 ]; then
{
#sqlplus pos/pos @bhml 2010060$i
echo 2010${k}0$i
}
else
{
#sqlplus pos/pos @bhml 201006$i
echo 2010$k$i
}
fi
done
done