Several commands used to modify a table

1. Modify empty columns with non-empty Columns

Update z_taxidriver

Set mobile = zzdh

Where mobileIs nullAnd zzdhIs not null

 

2. Create a table with a full outer join. Take a certain range of values in a column of the table.

Create TableCAs

Select A.1 A.2 B .1 B .2

FromFull outer joinB

OnA.3 = B .3 and A.1 in ('','');

3. Add some content to a field

Upadte a set A.1 =Concat('Nihao', A.1)

Concat (str1, str2, str3 ,...

Delete part of content

Update a set A.1 =Replace(A.1, '','')

Replace (''string _ replace1 '', ''string _ replace2'', ''string _ replace3 '')
Replace all the second given string expressions in the first string expression with the third expression.