diff --git a/.github/workflows/test-appsync-utils.yml b/.github/workflows/test-appsync-utils.yml
index d7139ab..8260918 100644
--- a/.github/workflows/test-appsync-utils.yml
+++ b/.github/workflows/test-appsync-utils.yml
@@ -11,7 +11,7 @@ on:
 
 env:
   LOCALSTACK_AUTH_TOKEN: ${{ secrets.LOCALSTACK_API_KEY }}
-  TEST_IMAGE_NAME: public.ecr.aws/lambda/nodejs:16
+  TEST_IMAGE_NAME: public.ecr.aws/lambda/nodejs:18
 
 jobs:
   unit-test:
@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 18
       - run: npm ci
       - run: npm test
 
@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 18
 
       - name: Pull test docker image
         run: docker pull $TEST_IMAGE_NAME
diff --git a/__tests__/__snapshots__/resolvers.test.js.snap b/__tests__/__snapshots__/resolvers.test.js.snap
index 3163981..3b6fe2e 100644
--- a/__tests__/__snapshots__/resolvers.test.js.snap
+++ b/__tests__/__snapshots__/resolvers.test.js.snap
@@ -38,6 +38,29 @@ exports[`dynamodb resolvers something 2`] = `
 ]
 `;
 
+exports[`rds resolvers attributeExists nested or 1`] = `
+{
+  "statements": [
+    "SELECT * FROM "supplier" WHERE "id" = :P0 AND (("deleted" = :P1) OR ("deleted" IS NULL))",
+  ],
+  "variableMap": {
+    ":P0": "123456",
+    ":P1": false,
+  },
+  "variableTypeHintMap": {},
+}
+`;
+
+exports[`rds resolvers attributeExists true false 1`] = `
+{
+  "statements": [
+    "SELECT * FROM "supplier" WHERE "created" IS NOT NULL AND "deleted" IS NULL",
+  ],
+  "variableMap": {},
+  "variableTypeHintMap": {},
+}
+`;
+
 exports[`rds resolvers mysql insert 1`] = `
 {
   "statements": [
@@ -362,3 +385,73 @@ exports[`rds resolvers typehints UUID 1`] = `
   "value": "abc123",
 }
 `;
+
+exports[`rds resolvers where mixed inline and 1`] = `
+{
+  "statements": [
+    "SELECT * FROM "supplier" WHERE "count" <= :P0 AND ("id" = :P1) AND "deleted" IS NULL",
+  ],
+  "variableMap": {
+    ":P0": 10,
+    ":P1": 123456,
+  },
+  "variableTypeHintMap": {},
+}
+`;
+
+exports[`rds resolvers where mixed or/and 1`] = `
+{
+  "statements": [
+    "SELECT * FROM "supplier" WHERE ("id" = :P0) AND ("id" = :P1) AND "id" = :P2",
+  ],
+  "variableMap": {
+    ":P0": "and eq",
+    ":P1": "or eq 2",
+    ":P2": "id eq",
+  },
+  "variableTypeHintMap": {},
+}
+`;
+
+exports[`rds resolvers where mixed or/and multiple or 1`] = `
+{
+  "statements": [
+    "SELECT * FROM "supplier" WHERE ("id" = :P0) AND ("id" = :P1) OR ("id" = :P2) AND "id" = :P3",
+  ],
+  "variableMap": {
+    ":P0": "and eq",
+    ":P1": "or eq 1",
+    ":P2": "or eq 2",
+    ":P3": "id eq",
+  },
+  "variableTypeHintMap": {},
+}
+`;
+
+exports[`rds resolvers where nested ors with ands 1`] = `
+{
+  "statements": [
+    "SELECT * FROM "supplier" WHERE "id" = :P0 AND ("id" = :P1) OR (("id" = :P2) OR ("id" = :P3)) OR ("id" = :P4)",
+  ],
+  "variableMap": {
+    ":P0": "id eq",
+    ":P1": "or 1",
+    ":P2": "or nested 1",
+    ":P3": "or nested 2",
+    ":P4": "final or",
+  },
+  "variableTypeHintMap": {},
+}
+`;
+
+exports[`rds resolvers where single value in and 1`] = `
+{
+  "statements": [
+    "SELECT * FROM "supplier" WHERE ("id" = :P0)",
+  ],
+  "variableMap": {
+    ":P0": 123456,
+  },
+  "variableTypeHintMap": {},
+}
+`;
diff --git a/__tests__/resolvers.test.js b/__tests__/resolvers.test.js
index 907f79f..59d6660 100644
--- a/__tests__/resolvers.test.js
+++ b/__tests__/resolvers.test.js
@@ -225,7 +225,7 @@ describe("rds resolvers", () => {
 
       const context = {
         arguments: {
-          id: new Date(2023, 1, 1),
+          id: new Date(Date.UTC(2023, 1, 1)),
         },
       };
 
@@ -503,6 +503,147 @@ describe("rds resolvers", () => {
     await checkResolverValid(code, responseContext, "response");
   })
 
+  test("where mixed inline and", async () => {
+    const code = `
+      export function request(ctx) {
+          const query = rds.select({
+              table: 'supplier',
+              where: {
+                count: { le: 10 },
+                and: [{ id: { eq: 123456 } }],
+                deleted: { attributeExists: false }
+              }
+          });
+          return rds.createPgStatement(query);
+      }
+      export function response(ctx) {}
+  `;
+    await checkResolverValid(code, {}, "request");
+  })
+
+  test("where single value in and", async () => {
+    const code = `
+      export function request(ctx) {
+          const query = rds.select({
+              table: 'supplier',
+              where: {
+                and: [{ id: { eq: 123456 } }],
+              }
+          });
+          return rds.createPgStatement(query);
+      }
+      export function response(ctx) {}
+  `;
+    await checkResolverValid(code, {}, "request");
+  })
+
+  test("where mixed or/and", async () => {
+    const code = `
+      export function request(ctx) {
+          const query = rds.select({
+              table: 'supplier',
+              where: {
+                and: [{ id: { eq: "and eq" } }],
+                or: [{ id: { eq: "or eq 2" } }],
+                id: { eq: "id eq" },
+              }
+          });
+          return rds.createPgStatement(query);
+      }
+      export function response(ctx) {}
+  `;
+    await checkResolverValid(code, {}, "request");
+  })
+
+  test("where mixed or/and multiple or", async () => {
+    const code = `
+      export function request(ctx) {
+          const query = rds.select({
+              table: 'supplier',
+              where: {
+                and: [{ id: { eq: "and eq" } }],
+                or: [
+                  { id: { eq: "or eq 1" } },
+                  { id: { eq: "or eq 2" } }
+                ],
+                id: { eq: "id eq" },
+              }
+          });
+          return rds.createPgStatement(query);
+      }
+      export function response(ctx) {}
+  `;
+    await checkResolverValid(code, {}, "request");
+  })
+
+  test("where nested ors with ands", async () => {
+    const code = `
+      export function request(ctx) {
+          const query = rds.select({
+              table: 'supplier',
+              where: {
+                id: { eq: "id eq" },
+                or: [
+                  { id: { eq: "or 1" } },
+                  {
+                    or: [
+                      { id: { eq: "or nested 1" } },
+                      { id: { eq: "or nested 2" } }
+                    ]
+                  },
+                  { id: { eq: "final or" } }
+                ]
+              }
+          });
+          return rds.createPgStatement(query);
+      }
+      export function response(ctx) {}
+  `;
+    await checkResolverValid(code, {}, "request");
+  })
+
+  test("attributeExists true false", async () => {
+    const code = `
+      export function request(ctx) {
+          const query = rds.select({
+              table: 'supplier',
+              where: {
+                created: { attributeExists: true },
+                deleted: { attributeExists: false }
+              }
+          });
+          return rds.createPgStatement(query);
+      }
+      export function response(ctx) {}
+  `;
+    await checkResolverValid(code, {}, "request");
+  })
+
+  test("attributeExists nested or", async () => {
+    const code = `
+      export function request(ctx) {
+          const query = rds.select({
+              table: 'supplier',
+              where: {
+                  id: {
+                      eq: "123456"
+                  },
+                  and: [{
+                      or: [
+                          { deleted: { eq: false } },
+                          { deleted: { attributeExists: false } }
+                      ]
+                  }
+                  ]
+              }
+          });
+          return rds.createPgStatement(query);
+      }
+      export function response(ctx) {}
+  `;
+  await checkResolverValid(code, {}, "request");
+  })
+
 
   describe("mysql", () => {
     test("raw string", async () => {
@@ -566,7 +707,7 @@ describe("rds resolvers", () => {
         arguments: {
           id: "1232",
           name: "hello",
-          started: new Date(2022, 2, 2),
+          started: new Date(Date.UTC(2022, 2, 2)),
         }
       };
 
@@ -757,7 +898,7 @@ describe("rds resolvers", () => {
         arguments: {
           id: "1232",
           name: "hello",
-          started: new Date(2022, 2, 2),
+          started: new Date(Date.UTC(2022, 2, 2)),
         }
       };
 
diff --git a/rds/index.js b/rds/index.js
index e452757..1c943cc 100644
--- a/rds/index.js
+++ b/rds/index.js
@@ -273,26 +273,28 @@ class StatementBuilder {
     return name;
   }
 
-  buildWhereClause(where) {
+  buildWhereClause(where, startGrouping = "", endGrouping = "", default_operator="AND") {
     let blocks = [];
-    if (where.or) {
-      const parts = [];
-      for (const part of where.or) {
-        parts.push(this.buildWhereStatement(part));
-      }
-      blocks.push(parts.join(" OR "));
-    } else if (where.and) {
-      const parts = [];
-      for (const part of where.and) {
-        parts.push(this.buildWhereStatement(part));
+    for (const key in where) {
+      if ( ["or", "and"].includes(key)) {
+        const ops = key.toUpperCase();
+        if (!Array.isArray(where[key])) {
+          // TODO properly handle errors to return a more useful message
+          throw new Error(`'${key}' expects conditions to be an array`);
+        }
+        const parts = where[key].map(
+          part => this.buildWhereClause(part, "(", ")", ops)
+        );
+        blocks.push(`${startGrouping}${parts.join(` ${ops} `)}${endGrouping}`);
+      } else {
+        // implicit single clause
+        const block = {};
+        block[key] = where[key];
+        blocks.push(this.buildWhereStatement(block, startGrouping, endGrouping));
       }
-      blocks.push(parts.join(" AND "));
-    } else {
-      // implicit single clause
-      blocks.push(this.buildWhereStatement(where, "", ""));
     }
 
-    return blocks;
+    return blocks.join(` ${default_operator} `);
   }
 
   buildWhereStatement(defn, startGrouping = "(", endGrouping = ")") {
@@ -300,7 +302,12 @@ class StatementBuilder {
     const condition = defn[columnName];
 
     const conditionType = Object.keys(condition)[0];
-    const value = this.newVariable(condition[conditionType]);
+    let value;
+    if (conditionType !== "attributeExists") {
+      value = this.newVariable(condition[conditionType]);
+    } else {
+      value = condition[conditionType];
+    }
     switch (conditionType) {
       case "eq":
         return `${startGrouping}${this.quoteChar}${columnName}${this.quoteChar} = ${value}${endGrouping}`;
@@ -318,6 +325,8 @@ class StatementBuilder {
         return `${startGrouping}${this.quoteChar}${columnName}${this.quoteChar} LIKE ${value}${endGrouping}`;
       case "notContains":
         return `${startGrouping}${this.quoteChar}${columnName}${this.quoteChar} NOT LIKE ${value}${endGrouping}`;
+      case "attributeExists":
+        return `${startGrouping}${this.quoteChar}${columnName}${this.quoteChar} IS ${value? "NOT " : ""}NULL${endGrouping}`;
       default:
         throw new Error(`Unhandled condition type ${conditionType}`);
     }
diff --git a/test_in_docker.sh b/test_in_docker.sh
index d670b67..8dd29d3 100755
--- a/test_in_docker.sh
+++ b/test_in_docker.sh
@@ -18,7 +18,7 @@ if [ -z ${TEST_IN_DOCKER_ENTRYPOINT:-} ]; then
         --workdir /test \
         --entrypoint bash \
         -e TEST_IN_DOCKER_ENTRYPOINT=1 \
-        ${TEST_IMAGE_NAME:-public.ecr.aws/lambda/nodejs:16} /test_in_docker.sh
+        ${TEST_IMAGE_NAME:-public.ecr.aws/lambda/nodejs:18} /test_in_docker.sh
 else
     # entrypoint
     echo Entrypoint