matching new line in Scala regex, when reading from file - regex

Question

For processing a file with SQL statements such as:
ALTER TABLE ONLY the_schema.the_big_table
ADD CONSTRAINT the_schema_the_big_table_pkey PRIMARY KEY (the_id);
I am using the regex:
val primaryKeyConstraintNameCatchingRegex: Regex = "([a-z]|_)+\\.([a-z]|_)+\n\\s*(ADD CONSTRAINT)\\s*([a-z]|_)+\\s*PRIMARY KEY”.r
Now the problem is that this regex does not return any results, despite the fact that both the regex
val alterTableRegex = “ALTER TABLE ONLY\\s+([a-z]|_)+\\.([a-z]|_)+”.r
and
val addConstraintRegex = “ADD CONSTRAINT\\s*([a-z]|_)+\\s*PRIMARY KEY”.r
match the intended sequences.
I thought the problem could be with the new line, and, so far, I have tried writing \\s+, \\W+, \\s*, \\W*, \\n*, \n*, \n+, \r+, \r*, \r\\s*, \n*\\s*, \\s*\n*\\s*, and other combinations to match the white space between the table name and add constraint to no avail.
I would appreciate any help with this.
Edit
This is the code I am using:
import scala.util.matching.Regex
import java.io.File
import scala.io.Source
object Hello extends Greeting with App {
val primaryKeyConstraintNameCatchingRegex: Regex = "([a-z]|_)+\\.([a-z]|_)+\r\\s*(ADD CONSTRAINT)\\s*([a-z]|_)+\\s*PRIMARY KEY".r
readFile
def readFile: Unit = {
val fname = "dump.sql"
val fSource = Source.fromFile(fname)
for (line <- fSource.getLines) {
val matchExp = primaryKeyConstraintNameCatchingRegex.findAllIn(line).foreach(
segment => println(segment)
)
}
fSource.close()
}
}
Edit 2
Another strange behavior is that when matching with
"""[a-z_]+(\.[a-z_]+)\s*A""”.r
the matches happen and they include A, but when I use
"""[a-z_]+(\.[a-z_]+)\s*ADD""”.r
which is only different in DD, no sequence is matched.

Answer 1

Your problem is that you read the file line by line (see for (line <- fSource.getLines) code part).
You need to grab the contents as a single string to be able to match across line breaks.
val fSource = Source.fromFile(fname).mkString
val matchExps = primaryKeyConstraintNameCatchingRegex.findAllIn(fSource)
Now, fSource will contain the whole text file contents as one string and matchExps will contain all found matches.