Can I Import an updated structure into a MySQL table without losing its current content?

Question

We use MySQL tables to which we add new fields from time to time as our product evolves. I\'m looking for a way to export the structure of the table from one copy of the db, to

Answer 1

I just had the same problem and solved it this way:

Export the structure of the table to update. Export the structure of the development table.

run this code for the first file "update.sql" needs to be changed according to your exported filename.

cat update.sql|awk -F / '{
 if(match($0, "CREATE TABLE")) {
   { FS = "`" } ; table = $2
 } else {
   if(match($0,"  `")) {
     gsub(",",";",$0)
     print "ALTER TABLE `" table "` ADD" $0
    }
 }
}' > update_alter.sql

run the same command for the second file

cat development.sql|awk -F / '{
 if(match($0, "CREATE TABLE")) {
   { FS = "`" } ; table = $2
 } else {
   if(match($0,"  `")) {
     gsub(",",";",$0)
     print "ALTER TABLE `" table "` ADD" $0
    }
 }
}' > development_alter.sql

run this command to find the differences in the output files

diff --changed-group-format='%<' --unchanged-group-format='' development_alter.sql update_alter.sql > update_db.sql

In the file update_db.sql there will now be the code you are looking for.