使用laravel连接到现有的postgre cms数据库

Basically I have to build a cms and use existing Postgres database. Previous version was written in pure php and it must be reworked with Laravel. The thing is can't really use migrations because the match will not be exact, when switch from local to live db in the end. I got the .sql file which besides the tables got checks, constraints and altering tables statements like.

ALTER TABLE "categories" ADD CONSTRAINT "PK_categories"
    PRIMARY KEY ("idx")
;


   CREATE INDEX "IXFK_ps_settings_server_ps" ON "ps_settings" ("psid"  ASC);

ALTER TABLE "ps_settings" ADD CONSTRAINT "FK_ps_settings_server_ps"
    FOREIGN KEY ("psid") REFERENCES "server_ps" ("psid") ON DELETE No Action ON UPDATE No Action
;

Till now I always used schemas and did set relations in them(or in models), but now it does not seems like it. How i'm supposed to build this thing where I can't really use some of the best laravel features(migrations, schemas,)and have perfect sync with the current db in the end ?