LinuxQuestions.org - text processing to modify sql create script

I have a large number of sql scripts that I'd like to process.

Code:

CREATE TABLE WAREHOUSE_OBJECT

(

  OBJECT_ID          numeric(15)  NOT NULL,

  OBJECT_IDENTIFIER  char(32)      NOT NULL

);



CREATE UNIQUE INDEX  S_WAREHOUSE_OBJECT_PK ON  S_WAREHOUSE_OBJECT

(CONFIG_ID);



ALTER TABLE  S_WAREHOUSE_OBJECT ADD(  --remove open bracket here

  CONSTRAINT S_WAREHOUSE_OBJECT_PK

 PRIMARY KEY

 (CONFIG_ID));  -- remove last close bracket here

I'd like to remove open/closed brackets (at ALTER TABLE) so it looks like this.

Code:

CREATE TABLE WAREHOUSE_OBJECT

(

  OBJECT_ID          numeric(15)  NOT NULL,

  OBJECT_IDENTIFIER  char(32)      NOT NULL

);



CREATE UNIQUE INDEX  S_WAREHOUSE_OBJECT_PK ON  S_WAREHOUSE_OBJECT

(CONFIG_ID);



ALTER TABLE  S_WAREHOUSE_OBJECT ADD 

  CONSTRAINT S_WAREHOUSE_OBJECT_PK

 PRIMARY KEY

 (CONFIG_ID);

I tried something like this in awk but not sure how to eliminate the brackets :(

Code:

BEGIN {OFS=" "}

  $1 =="ALTER"      { x=$0 }

  $1 =="CONSTRAINT" { y=$0}

  $1 =="PRIMARY"    { z=$0}

  $1 =="((" {print x, y, z, $0}