diff --git a/‎packages/react-pg/src/ReactPostgres.js‎
Lines changed: 19 additions & 2 deletions b/‎packages/react-pg/src/ReactPostgres.js‎
Lines changed: 19 additions & 2 deletions
diff --git a/‎scripts/error-codes/codes.json‎
Lines changed: 3 additions & 1 deletion b/‎scripts/error-codes/codes.json‎
Lines changed: 3 additions & 1 deletion
@@ -12,6 +12,7 @@ import type {Wakeable} from 'shared/ReactTypes';
 import {unstable_getCacheForType} from 'react';
 import {Pool as PostgresPool} from 'pg';
 import {prepareValue} from 'pg/lib/utils';
+import invariant from 'shared/invariant';
 
 const Pending = 0;
 const Resolved = 1;
@@ -74,11 +75,13 @@ export function Pool(options: mixed) {
   };
 }
 
+type NestedMap = Map<any, Result | NestedMap>;
+
 Pool.prototype.query = function(query: string, values?: Array<mixed>) {
   const pool = this.pool;
   const outerMap = unstable_getCacheForType(this.createResultMap);
 
-  let innerMap: Map<any, any> = outerMap;
+  let innerMap: NestedMap = outerMap;
   let key = query;
   if (values != null) {
     // If we have parameters, each becomes as a nesting layer for Maps.
@@ -88,6 +91,13 @@ Pool.prototype.query = function(query: string, values?: Array<mixed>) {
       if (nextMap === undefined) {
         nextMap = new Map();
         innerMap.set(key, nextMap);
+      } else if (!(nextMap instanceof Map)) {
+        invariant(
+          false,
+          'This query has received more parameters than the last time ' +
+            'the same query was used. Always pass the exact number of ' +
+            'parameters that the query needs.',
+        );
       }
       innerMap = nextMap;
       // Postgres bindings convert everything to strings:
@@ -97,11 +107,18 @@ Pool.prototype.query = function(query: string, values?: Array<mixed>) {
     }
   }
 
-  let entry: Result | void = innerMap.get(key);
+  let entry = innerMap.get(key);
   if (!entry) {
     const thenable = pool.query(query, values);
     entry = toResult(thenable);
     innerMap.set(key, entry);
+  } else if (entry instanceof Map) {
+    invariant(
+      false,
+      'This query has received fewer parameters than the last time ' +
+        'the same query was used. Always pass the exact number of ' +
+        'parameters that the query needs.',
+    );
   }
   return readResult(entry);
 };
@@ -369,5 +369,7 @@
   "378": "Type %s is not supported in client component props. Remove %s from this object, or avoid the entire object: %s",
   "379": "Refs cannot be used in server components, nor passed to client components.",
   "380": "Reading the cache is only supported while rendering.",
-  "381": "This feature is not supported by ReactSuspenseTestUtils."
+  "381": "This feature is not supported by ReactSuspenseTestUtils.",
+  "382": "This query has received more parameters than the last time the same query was used. Always pass the exact number of parameters that the query needs.",
+  "383": "This query has received fewer parameters than the last time the same query was used. Always pass the exact number of parameters that the query needs."
 }
Original file line number	Diff line number	Diff line change
`@@ -369,5 +369,7 @@`
`369`	`369`	`"378": "Type %s is not supported in client component props. Remove %s from this object, or avoid the entire object: %s",`
`370`	`370`	`"379": "Refs cannot be used in server components, nor passed to client components.",`
`371`	`371`	`"380": "Reading the cache is only supported while rendering.",`
`372`		`- "381": "This feature is not supported by ReactSuspenseTestUtils."`
	`372`	`+ "381": "This feature is not supported by ReactSuspenseTestUtils.",`
	`373`	`+ "382": "This query has received more parameters than the last time the same query was used. Always pass the exact number of parameters that the query needs.",`
	`374`	`+ "383": "This query has received fewer parameters than the last time the same query was used. Always pass the exact number of parameters that the query needs."`
`373`	`375`	`}`