feat(cmd/vet): Prepare queries against a database (#2387)

* feat(cmd/vet): Prepare queries against a database

If configured, prepare queries against a running database

* test: Attempt to create a database for each example

* test(examples): Run vet for all examples

* Don't create databases twice

Author: kyleconroy

examples/authors/sqlc.json

@@ -5,6 +5,9 @@
       "schema": "postgresql/schema.sql",
       "queries": "postgresql/query.sql",
       "engine": "postgresql",
+      "database": {
+        "url": "'postgresql://%s:%s@%s:%s/authors'.format([env.PG_USER, env.PG_PASSWORD, env.PG_HOST, env.PG_PORT])"
+      },
       "gen": {
         "go": {
           "package": "authors",

examples/batch/sqlc.json

@@ -7,6 +7,9 @@
       "schema": "postgresql/schema.sql",
       "queries": "postgresql/query.sql",
       "engine": "postgresql",
+      "database": {
+        "url": "'postgresql://%s:%s@%s:%s/batch'.format([env.PG_USER, env.PG_PASSWORD, env.PG_HOST, env.PG_PORT])"
+      },
       "sql_package": "pgx/v4",
       "emit_json_tags": true,
       "emit_prepared_queries": true,

examples/booktest/sqlc.json

@@ -6,7 +6,10 @@
       "path": "postgresql",
       "schema": "postgresql/schema.sql",
       "queries": "postgresql/query.sql",
-      "engine": "postgresql"
+      "engine": "postgresql",
+      "database": {
+        "url": "'postgresql://%s:%s@%s:%s/booktest'.format([env.PG_USER, env.PG_PASSWORD, env.PG_HOST, env.PG_PORT])"
+      }
     },
     {
       "name": "booktest",

examples/jets/db.go examples/jets/postgresql/db.goexamples/jets/db.go renamed to examples/jets/postgresql/db.go

@@ -2,11 +2,14 @@
   "version": "1",
   "packages": [
     {
-      "path": ".",
+      "path": "postgresql",
       "name": "jets",
-      "schema": "schema.sql",
-      "queries": "query-building.sql",
-      "engine": "postgresql"
+      "schema": "postgresql/schema.sql",
+      "queries": "postgresql/query-building.sql",
+      "engine": "postgresql",
+      "database": {
+        "url": "'postgresql://%s:%s@%s:%s/jets'.format([env.PG_USER, env.PG_PASSWORD, env.PG_HOST, env.PG_PORT])"
+      }
     }
   ]
 }

examples/jets/models.go examples/jets/postgresql/models.goexamples/jets/models.go renamed to examples/jets/postgresql/models.go

@@ -39,8 +39,8 @@
       ]
     },
     {
-      "schema": "src/main/resources/jets/schema.sql",
-      "queries": "src/main/resources/jets/query-building.sql",
+      "schema": "src/main/resources/jets/postgresql/schema.sql",
+      "queries": "src/main/resources/jets/postgresql/query-building.sql",
       "engine": "postgresql",
       "codegen": [
         {