Fixing some issues highlighted by test case.

packages/server/src/api/routes/tests/datasource.spec.ts

@@ -258,11 +258,12 @@ describe("/datasources", () => {
           })
         )
 
+        const stringName = "string"
         const fullSchema: {
           [type in SupportedSqlTypes]: FieldSchema & { type: type }
         } = {
           [FieldType.STRING]: {
-            name: "string",
+            name: stringName,
             type: FieldType.STRING,
             constraints: {
               presence: true,
@@ -353,6 +354,10 @@ describe("/datasources", () => {
                   ),
                   schema: Object.entries(table.schema).reduce<TableSchema>(
                     (acc, [fieldName, field]) => {
+                      // the constraint will be unset - as the DB doesn't recognise it as not null
+                      if (fieldName === stringName) {
+                        field.constraints = {}
+                      }
                       acc[fieldName] = expect.objectContaining({
                         ...field,
                       })

packages/server/src/integrations/utils/utils.ts

@@ -289,19 +289,25 @@ function copyExistingPropsOver(
           externalType:
             existingTableSchema[key].externalType ||
             table.schema[key]?.externalType,
-          autocolumn: !!fetchedColumnDefinition?.autocolumn,
+          autocolumn: fetchedColumnDefinition?.autocolumn,
         } as FieldSchema
         // check constraints which can be fetched from the DB (they could be updated)
         if (fetchedColumnDefinition?.constraints) {
           // inclusions are the enum values (select/options)
-          const fetchedInclusion = fetchedColumnDefinition.constraints.inclusion
-          const oldInclusion = table.schema[key].constraints?.inclusion
+          const fetchedConstraints = fetchedColumnDefinition.constraints
+          const oldConstraints = table.schema[key].constraints
           table.schema[key].constraints = {
             ...table.schema[key].constraints,
-            presence: !!fetchedColumnDefinition.constraints?.presence,
-            inclusion: fetchedInclusion?.length
-              ? fetchedInclusion
-              : oldInclusion,
+            inclusion: fetchedConstraints.inclusion?.length
+              ? fetchedConstraints.inclusion
+              : oldConstraints?.inclusion,
+          }
+          // true or undefined - consistent with old API
+          if (fetchedConstraints.presence) {
+            table.schema[key].constraints!.presence =
+              fetchedConstraints.presence
+          } else if (oldConstraints?.presence === true) {
+            delete table.schema[key].constraints?.presence
           }
         }
       }