Question

I have two files. One is a file of table creation strings dumped from database, the other is the name of tables, with a “prompt” as a prefix and a “…” as suffix. Just as below:
file A (index):

prompt branch...
prompt branch_param...
prompt branch_pre_param...
prompt business...
prompt business_map...
prompt business_type...

file B (dump):

CREATE TABLE "KS"."BRANCH"
 ("BRANCH_CODE"       CHARACTER(3)    NOT NULL  DEFAULT '',
  "BRANCH_NAME"       CHARACTER(40)   NOT NULL  DEFAULT '',
  "PARAM_LEVEL"       INTEGER         NOT NULL  DEFAULT 0
 )
  DATA CAPTURE NONE
 IN "LONG_DATA_TBS";


CREATE TABLE "KS"."BRANCH2BANK"
 ("BRANCH_CODE"         CHARACTER(3)    NOT NULL  DEFAULT '',
  "BANK_CODE"           CHARACTER(6)    NOT NULL  DEFAULT '',
  "ACC_COMP_RESULT"     CHARACTER(1)    NOT NULL  DEFAULT ''
 )
  DATA CAPTURE NONE
 IN "SMALL_TBS";

CREATE TABLE "KS"."BRANCH2BOND"
 ("BRANCH_CODE"        CHARACTER(3)    NOT NULL  DEFAULT '',
  "BOND_CODE"          CHARACTER(8)    NOT NULL  DEFAULT '',
  "BOND_NAME"          CHARACTER(20)   NOT NULL  DEFAULT '',
  "TOTAL_AMT"          DECIMAL(19, 4)  NOT NULL  DEFAULT 0,
  "FINANCING_CUST_NO"  CHARACTER(10)   NOT NULL  DEFAULT '',
  "SET_DATE"           CHARACTER(8)    NOT NULL  DEFAULT '',
  "SET_TIME"           CHARACTER(8)    NOT NULL  DEFAULT '',
  "SET_EMP"            CHARACTER(6)    NOT NULL  DEFAULT '',
  "SPARE1"             CHARACTER(20)   NOT NULL  DEFAULT '',
  "SPARE2"             CHARACTER(20)   NOT NULL  DEFAULT ''
 )
  DATA CAPTURE NONE
 IN "SMALL_TBS";

CREATE TABLE "KS"."BRANCH_PARAM"
 ("BRANCH_CODE"    CHARACTER(3)    NOT NULL  DEFAULT '',
  "PARAM_CODE"     CHARACTER(4)    NOT NULL  DEFAULT '',
  "SET_DATE"       CHARACTER(8)    NOT NULL  DEFAULT '',
  "SET_TIME"       CHARACTER(8)    NOT NULL  DEFAULT ''
 )
  DATA CAPTURE NONE
 IN "SMALL_TBS";

CREATE TABLE "KS"."BRANCH_RESERVE_CREDIT_STOCK"
 ("BRANCH_CODE"  CHARACTER(3)    NOT NULL  DEFAULT '',
  "SET_TIME"     CHARACTER(8)    NOT NULL  DEFAULT ''
 )
  DATA CAPTURE NONE
 IN "TX_DATA_TBS"
 INDEX IN "TX_INDEX_TBS";

I have written a perl implementation, but I think it is much too ugly and inefficient. Is there a better way to improve this?

my code: (rewritten with Richard and lilydjwg’s advice) (last version)

#!/usr/bin/perl
use 5.016;

my (%hash,$cont);
open IN,'<',shift;
while(<IN>){
    chomp;
    $hash{$1}=1 if /prompt (\w+)\.\.\./;
}
close IN;
open IN,'<',shift;
while(<IN>){
    chomp;
    $cont = (defined $hash{lc $1}?say "prompt $1..." : 0) if /CREATE TABLE "KS"\."(\w+)"/;
    say if $cont == 1;
}
close IN;                   

Answer 1

Presumably it’s the repeated reads you don’t like.

So – read the CREATE TABLE file once, checking for:

CREATE TABLE "KS"."(\w+)"

Then you can build up the table definition until the next CREATE TABLE at which point you put the table-definition into a hash keyed by the table-name.

Then, read your prompts and grab the definitions one by one from the hash printing them out.

Alternatively, you could just read the CREATE TABLE file into a single string and search+replace the table-name part since that’s all you seem to be changing at the moment. The first approach is more flexible though.

---

Edit:
You could make the defined bit a little clearer perhaps with:

while ($line=<IN>) {
    chomp($line);
    if (/CREATE TABLE "KS"\."(\w+)"/ && $hash{lc $1}) {
        $line = ...
    }
    say $line;
}

I like to use an explicit variable in my while-loops once I get beyond a couple of lines too.