Add Zotero.DB.columnExists(table, column)

chrome/content/zotero/xpcom/db.js

@@ -799,6 +799,14 @@ Zotero.DBConnection.prototype.tableExists = Zotero.Promise.coroutine(function* (
 });
 
 
+Zotero.DBConnection.prototype.columnExists = async function (table, column) {
+	await this._getConnectionAsync();
+	var sql = `SELECT COUNT(*) FROM pragma_table_info(?) WHERE name=?`;
+	var count = await this.valueQueryAsync(sql, [table, column]);
+	return !!count;
+};
+
+
 /**
  * Parse SQL string and execute transaction with all statements
  *

test/tests/dbTest.js

@@ -341,4 +341,19 @@ describe("Zotero.DB", function() {
 			assert.ok(callback2Ran);
 		});
 	})
+	
+	
+	describe("#columnExists()", function () {
+		it("should return true if a column exists", async function () {
+			assert.isTrue(await Zotero.DB.columnExists('items', 'itemID'));
+		});
+		
+		it("should return false if a column doesn't exists", async function () {
+			assert.isFalse(await Zotero.DB.columnExists('items', 'foo'));
+		});
+		
+		it("should return false if a table doesn't exists", async function () {
+			assert.isFalse(await Zotero.DB.columnExists('foo', 'itemID'));
+		});
+	});
 });