标签云

微信群

扫码加入我们

WeChat QR Code

Oracle连接表[复制]

This question already has an answer here:

I have

T1: USER_ID OSX
       1     Y
       2     Y  

T2: USER_ID ANDROID
       1     Y
       3     Y  

I want to join the tables as follows but i don't know how

T3: USER_ID ANDROID  OSX
       1     Y        Y
       2     null     Y
       3     Y        null


null is null, why should one want a dummy-value 'N/A' on the database-layer?!

2018年06月19日33分13秒