Add x-stackQL-config queryParamPushdown for OData and custom API predicate pushdown

.claude/skills/stackql-provider-development.md

@@ -521,6 +521,238 @@ sqlExternalTables:
         precision: integer
 ```
 
+### Query Parameter Pushdown (`queryParamPushdown`)
+
+Enables SQL clause pushdown to API query parameters. Supports OData and custom API dialects for filter, projection, ordering, and limit operations.
+
+**Location:** Can be set at **provider, providerService, service, resource, or method level**. Config inherits from higher levels, with lower levels overriding higher levels:
+
+```
+Method -> Resource -> Service -> ProviderService -> Provider
+```
+
+This allows you to set a default OData config at the service level and have all resources/methods inherit it, while still allowing specific methods to override with custom settings.
+
+```yaml
+x-stackQL-config:
+  queryParamPushdown:
+    # Column projection (SELECT clause pushdown)
+    select:
+      dialect: odata | custom    # "custom" is default; "odata" applies OData defaults
+      paramName: "$select"       # Not required for OData (default: "$select")
+      delimiter: ","             # Not required for OData (default: ",")
+      supportedColumns:          # Optional, omit or ["*"] for all columns
+        - "id"
+        - "name"
+        - "status"
+
+    # Row filtering (WHERE clause pushdown)
+    filter:
+      dialect: odata | custom    # "custom" is default; "odata" applies OData defaults
+      paramName: "$filter"       # Not required for OData (default: "$filter")
+      syntax: odata              # Not required for OData (default: "odata")
+      supportedOperators:        # Required - which operators can be pushed down
+        - "eq"
+        - "ne"
+        - "gt"
+        - "lt"
+        - "ge"
+        - "le"
+        - "contains"
+        - "startswith"
+      supportedColumns:          # Optional, omit or ["*"] for all columns
+        - "displayName"
+        - "status"
+        - "createdDate"
+
+    # Ordering (ORDER BY clause pushdown)
+    orderBy:
+      dialect: odata | custom    # "custom" is default; "odata" applies OData defaults
+      paramName: "$orderby"      # Not required for OData (default: "$orderby")
+      syntax: odata              # Not required for OData (default: "odata")
+      supportedColumns:          # Optional, omit or ["*"] for all columns
+        - "name"
+        - "createdDate"
+
+    # Row limit (LIMIT clause pushdown)
+    top:
+      dialect: odata | custom    # "custom" is default; "odata" applies OData defaults
+      paramName: "$top"          # Not required for OData (default: "$top")
+      maxValue: 1000             # Optional, cap on pushdown value
+
+    # Count (SELECT COUNT(*) pushdown)
+    count:
+      dialect: odata | custom    # "custom" is default; "odata" applies OData defaults
+      paramName: "$count"        # Not required for OData (default: "$count")
+      paramValue: "true"         # Not required for OData (default: "true")
+      responseKey: "@odata.count"# Not required for OData (default: "@odata.count")
+```
+
+**Minimal OData Configuration:**
+
+When using OData dialect, defaults are applied automatically:
+
+```yaml
+x-stackQL-config:
+  queryParamPushdown:
+    select: {}
+    filter:
+      dialect: odata
+      supportedOperators: ["eq", "ne", "gt", "lt", "contains"]
+    orderBy:
+      dialect: odata
+    top:
+      dialect: odata
+    count:
+      dialect: odata
+```
+
+**Custom API Configuration:**
+
+For APIs with custom query parameter names:
+
+```yaml
+x-stackQL-config:
+  queryParamPushdown:
+    select:
+      paramName: "fields"
+      delimiter: ","
+    filter:
+      paramName: "filter"
+      syntax: "key_value"        # filter[status]=active&filter[region]=us-east-1
+      supportedOperators:
+        - "eq"
+      supportedColumns:
+        - "status"
+        - "region"
+    orderBy:
+      paramName: "sort"
+      syntax: "prefix"           # sort=-createdAt (prefix - for desc)
+      supportedColumns:
+        - "createdAt"
+        - "name"
+    top:
+      paramName: "limit"
+      maxValue: 100
+    count:
+      paramName: "include_count"
+      paramValue: "1"
+      responseKey: "meta.total"
+```
+
+**Supported Filter Syntaxes:**
+
+| Syntax | Example Output | Use Case |
+|--------|---------------|----------|
+| `odata` | `$filter=status eq 'active' and region eq 'us-east-1'` | OData APIs |
+| `key_value` | `filter[status]=active&filter[region]=us-east-1` | Rails-style APIs |
+| `simple` | `status=active&region=us-east-1` | Basic query params |
+
+**Supported OrderBy Syntaxes:**
+
+| Syntax | Example | Notes |
+|--------|---------|-------|
+| `odata` | `$orderby=name desc,date asc` | Space-separated direction |
+| `prefix` | `sort=-name,+date` | `-` for desc, `+` or none for asc |
+| `suffix` | `sort=name:desc,date:asc` | Colon-separated direction |
+
+**Column/Operator Support Logic:**
+
+| Value | Behavior |
+|-------|----------|
+| omitted / `null` | All items allowed |
+| `["*"]` | Explicit "all items" (same as omitted) |
+| `["col1", "col2"]` | Only these items supported |
+| `[]` | No items supported (effectively disabled) |
+
+**OData Example with Inheritance (TripPin Reference Service):**
+
+Set a default config at service level, then override at resource or method level as needed:
+
+```yaml
+# Service-level config - inherited by all resources/methods
+x-stackQL-config:
+  queryParamPushdown:
+    select:
+      dialect: odata
+    filter:
+      dialect: odata
+      supportedOperators:
+        - "eq"
+        - "ne"
+    orderBy:
+      dialect: odata
+    top:
+      dialect: odata
+    count:
+      dialect: odata
+
+components:
+  x-stackQL-resources:
+    # Inherits service-level config (no override needed)
+    airlines:
+      id: odata.trippin.airlines
+      name: airlines
+      methods:
+        list:
+          operation:
+            $ref: '#/paths/~1Airlines/get'
+          # No config - inherits from service level
+      sqlVerbs:
+        select:
+          - $ref: '#/components/x-stackQL-resources/airlines/methods/list'
+
+    # Resource-level override with full operator support
+    people:
+      id: odata.trippin.people
+      name: people
+      config:
+        queryParamPushdown:
+          filter:
+            dialect: odata
+            supportedOperators:
+              - "eq"
+              - "ne"
+              - "gt"
+              - "lt"
+              - "contains"
+              - "startswith"
+      methods:
+        list:
+          operation:
+            $ref: '#/paths/~1People/get'
+      sqlVerbs:
+        select:
+          - $ref: '#/components/x-stackQL-resources/people/methods/list'
+
+    # Method-level override with restricted columns
+    airports:
+      id: odata.trippin.airports
+      name: airports
+      methods:
+        list:
+          operation:
+            $ref: '#/paths/~1Airports/get'
+          config:
+            queryParamPushdown:
+              select:
+                dialect: odata
+                supportedColumns:
+                  - "Name"
+                  - "IcaoCode"
+              filter:
+                dialect: odata
+                supportedColumns:
+                  - "Name"
+                  - "IcaoCode"
+              top:
+                dialect: odata
+                maxValue: 100
+      sqlVerbs:
+        select:
+          - $ref: '#/components/x-stackQL-resources/airports/methods/list'
+```
+
 ---
 
 ## Method Definition

anysdk/config.go

@@ -21,6 +21,7 @@ type StackQLConfig interface {
 	GetVariations() (Variations, bool)
 	GetViews() map[string]View
 	GetExternalTables() map[string]SQLExternalTable
+	GetQueryParamPushdown() (QueryParamPushdown, bool)
 	//
 	isObjectSchemaImplicitlyUnioned() bool
 	setResource(rsc Resource)
@@ -36,6 +37,7 @@ type standardStackQLConfig struct {
 	Views                map[string]*standardViewContainer   `json:"views" yaml:"views"`
 	ExternalTables       map[string]standardSQLExternalTable `json:"sqlExternalTables" yaml:"sqlExternalTables"`
 	Auth                 *standardAuthDTO                    `json:"auth,omitempty" yaml:"auth,omitempty"`
+	QueryParamPushdown   *standardQueryParamPushdown         `json:"queryParamPushdown,omitempty" yaml:"queryParamPushdown,omitempty"`
 }
 
 func (qt standardStackQLConfig) JSONLookup(token string) (interface{}, error) {
@@ -48,6 +50,8 @@ func (qt standardStackQLConfig) JSONLookup(token string) (interface{}, error) {
 		return qt.RequestTranslate, nil
 	case "views":
 		return qt.Views, nil
+	case "queryParamPushdown":
+		return qt.QueryParamPushdown, nil
 	default:
 		return nil, fmt.Errorf("could not resolve token '%s' from QueryTranspose doc object", token)
 	}
@@ -126,6 +130,13 @@ func (cfg *standardStackQLConfig) GetAuth() (AuthDTO, bool) {
 	return cfg.Auth, cfg.Auth != nil
 }
 
+func (cfg *standardStackQLConfig) GetQueryParamPushdown() (QueryParamPushdown, bool) {
+	if cfg.QueryParamPushdown == nil {
+		return nil, false
+	}
+	return cfg.QueryParamPushdown, true
+}
+
 func (cfg *standardStackQLConfig) GetExternalTables() map[string]SQLExternalTable {
 	rv := make(map[string]SQLExternalTable, len(cfg.ExternalTables))
 	if cfg.ExternalTables != nil {

anysdk/operation_store.go

@@ -62,6 +62,7 @@ type OperationStore interface {
 	GetGraphQL() GraphQL
 	GetInverse() (OperationInverse, bool)
 	GetStackQLConfig() StackQLConfig
+	GetQueryParamPushdown() (QueryParamPushdown, bool)
 	GetParameters() map[string]Addressable
 	GetPathItem() *openapi3.PathItem
 	GetAPIMethod() string
@@ -405,6 +406,42 @@ func (op *standardOpenAPIOperationStore) getStackQLConfig() (StackQLConfig, bool
 	return rv, rv != nil
 }
 
+// GetQueryParamPushdown returns the queryParamPushdown config with inheritance.
+// It walks up the hierarchy: Method -> Resource -> Service -> ProviderService -> Provider
+func (op *standardOpenAPIOperationStore) GetQueryParamPushdown() (QueryParamPushdown, bool) {
+	// Check method-level config first
+	if op.StackQLConfig != nil {
+		if qpp, ok := op.StackQLConfig.GetQueryParamPushdown(); ok {
+			return qpp, true
+		}
+	}
+	// Check resource-level config
+	if op.Resource != nil {
+		if qpp, ok := op.Resource.GetQueryParamPushdown(); ok {
+			return qpp, true
+		}
+	}
+	// Check service-level config
+	if op.OpenAPIService != nil {
+		if qpp, ok := op.OpenAPIService.getQueryParamPushdown(); ok {
+			return qpp, true
+		}
+	}
+	// Check providerService-level config
+	if op.ProviderService != nil {
+		if qpp, ok := op.ProviderService.GetQueryParamPushdown(); ok {
+			return qpp, true
+		}
+	}
+	// Check provider-level config
+	if op.Provider != nil {
+		if qpp, ok := op.Provider.GetQueryParamPushdown(); ok {
+			return qpp, true
+		}
+	}
+	return nil, false
+}
+
 func (op *standardOpenAPIOperationStore) GetAPIMethod() string {
 	return op.APIMethod
 }

anysdk/provider.go

@@ -28,6 +28,7 @@ type Provider interface {
 	GetProviderServices() map[string]ProviderService
 	GetPaginationRequestTokenSemantic() (TokenSemantic, bool)
 	GetPaginationResponseTokenSemantic() (TokenSemantic, bool)
+	GetQueryParamPushdown() (QueryParamPushdown, bool)
 	GetProviderService(key string) (ProviderService, error)
 	getQueryTransposeAlgorithm() string
 	GetRequestTranslateAlgorithm() string
@@ -128,6 +129,13 @@ func (pr *standardProvider) GetPaginationResponseTokenSemantic() (TokenSemantic,
 	return pr.StackQLConfig.Pagination.ResponseToken, true
 }
 
+func (pr *standardProvider) GetQueryParamPushdown() (QueryParamPushdown, bool) {
+	if pr.StackQLConfig != nil {
+		return pr.StackQLConfig.GetQueryParamPushdown()
+	}
+	return nil, false
+}
+
 func (pr *standardProvider) MarshalJSON() ([]byte, error) {
 	return jsoninfo.MarshalStrictStruct(pr)
 }

anysdk/providerService.go

@@ -25,6 +25,7 @@ type ProviderService interface {
 	GetResourcesShallow() (ResourceRegister, error)
 	GetPaginationRequestTokenSemantic() (TokenSemantic, bool)
 	getPaginationResponseTokenSemantic() (TokenSemantic, bool)
+	GetQueryParamPushdown() (QueryParamPushdown, bool)
 	ConditionIsValid(lhs string, rhs interface{}) bool
 	GetID() string
 	GetServiceFragment(resourceKey string) (Service, error)
@@ -178,6 +179,13 @@ func (sv *standardProviderService) getPaginationResponseTokenSemantic() (TokenSe
 	return sv.StackQLConfig.Pagination.ResponseToken, true
 }
 
+func (sv *standardProviderService) GetQueryParamPushdown() (QueryParamPushdown, bool) {
+	if sv.StackQLConfig != nil {
+		return sv.StackQLConfig.GetQueryParamPushdown()
+	}
+	return nil, false
+}
+
 func (sv *standardProviderService) ConditionIsValid(lhs string, rhs interface{}) bool {
 	elem := sv.ToMap()[lhs]
 	return reflect.TypeOf(elem) == reflect.TypeOf(rhs)