Generate SQL with Powershell & Regex - sql

Question

I have the following ddl(Data definition language) structure in sql:
CREATE TABLE tablename(
key ...,
key1 ...,
u_version ...,
field1 ...,
field2 ...
)
CREATE UNIQUE clustered... (key ASC, key1 ASC)
Because I want to create multiple tables with that structure, only the name of tables, keys and field names are different. So I want to use Powershell script to scan every file in the directory and generate sql script for each file.
The generated script should look like this:
INSERT INTO tablename(key, key1, u_version, field1, field2)
SELECT key, key1, field1, field2
FROM tablename_temp t
WHERE NOT EXISTS (SELECT key, key1
FROM tablename l
WHERE l.key = t.key AND l.key1 = t.key1)
For tablename & table_name_tempdb, I use the following:
switch -Regex ( $line ) {
'(^\s*create\s+table\s+)(?<tablename>[^(]*)' {
$table_name = $matches["tablename"]
$table_name_tempdb="${table_name}_tmp"
break
}
}
Now I want to do the same to keys and other fields. Are there any suggestions?
My idea is to scan every lines from the CREATE TABLE to ")" and add every word begins with " " and ends with " " in a list. Lines before u_version are keys, the others are considered as fields and build query with those.

Answer 1

Here is a working example, based upon the information provided, that outputs the new SQL.
I tweaked you SQL (your insert as is would have failed). Also, if your input files differ from your example, the expression will need tweaking.
Reading content with -Raw allows the whole file to be parsed together.
dir *.sql |%{
$filecontents = Get-Content $_.FullName -Raw
$matches = [Regex]::Match($filecontents, "CREATE TABLE (?'tablename'[^( ]+)\((\W+(?'key'\w+)\W(?'type'[^,)])+[,)])+(\W+u_version\W([^,)])+[,)])(\W+(?'field'\w+)\W(?'type'[^,)])+[,)])+\W+CREATE UNIQUE")
$tablename = $matches.Groups["tablename"].Value
$keys = $matches.Groups["key"].Captures.Value
$fields = $matches.Groups["field"].Captures.Value
'=================================================================='
#"
INSERT INTO $tablename($($keys -join ','), u_version, $($fields -join ','))
SELECT $($keys -join ','), u_version, $($fields -join ',')
FROM $($tablename)_temp t
WHERE NOT EXISTS (SELECT 1
FROM $tablename l
WHERE $(($keys |% { "l.$_ = t.$_" }) -join ' AND '))
"#
}