Import IDB from ' IDB ';varDbpromise = Idb.open (' test-db ', 4,function(upgradedb) {Switch(upgradedb.oldversion) { Case0: //Keyval Store is already created at version 1 varKeyvalstore = Upgradedb.createobjectstore (' Keyval ')); Keyvalstore.put ("World", "Hello"); Case1: //New versionUpgradedb.createobjectstore (' People ', {keypath: ' name ')}); Case2: varPeoplestore = UpgradeDb.transaction.objectStore (' People ')); Peoplestore.createindex (' Animal ', ' favoriteanimal '); Case3: varPeoplestore = UpgradeDb.transaction.objectStore (' People ')); Peoplestore.createindex (' Age ', the ' age '); }});//read "Hello" in "Keyval"Dbpromise.then (function(db) {vartx = Db.transaction (' keyval ');//Open a transaction varKeyvalstore = Tx.objectstore (' keyval ');//Read the store returnKeyvalstore.get (' Hello ');//get value by key}). Then (function(val) {Console.log (' The value of ' Hello ' is: ', Val);}); Dbpromise.then (function(db) {vartx = Db.transaction (' People ', ' ReadWrite '); varPeoplestore = Tx.objectstore (' People ')); Peoplestore.put ({name:"John",//name is the keyAge:23, Favoriteanimal:' Cat ' }); Peoplestore.put ({name:"Joe",//name is the keyAge:21, Favoriteanimal:' Cat ' }); Peoplestore.put ({name:"Jie",//name is the keyAge:22, Favoriteanimal:' Dog ' }); Peoplestore.put ({name:"Jay",//name is the keyAge:24, Favoriteanimal:' Dog ' }); returnTx.complete;}). Then (function() {Console.log ("People is added");}); Dbpromise.then (function(db) {vartx = Db.transaction (' People ', ' ReadWrite '); varPeoplestore = Tx.objectstore (' People ')); varAgeindex = Peoplestore.index (' Age '); returnAgeindex. OpenCursor ();}). Then (function(cursor) {if(!cursor)return; returnCursor.Advance(1);//Skip The first person}). Then (function Logperson(cursor) {if(Cursor.value.name = = "Jie") { cursor. Delete(); // Delete } if(Cursor.value.name = = "Jay") {Console.log ("Cursor at:", Cursor.value.name); varJoe =Cursor.value; Joe.favoriteanimal= "Bird"; Cursor.update (Joe); // update } return cursor. Continue (). then (Logperson);}). Then (function() {Console.log ("Done");});
[PWA] 14. Loop cursor