Access sObject's (Salesforce Object Type) Fields and Its Record | Apex Developer Guide

There are multiple cases where you need to show sObjects records and its field in Lightning. For example: Consider a use case scenario where you need to have a dropdown and there are all sObjects of your organization, you have to select the sObject and show the selected sObject’s fields.

For this, we have to select all the sObject in Apex class. 

public static List <sObject> getsAllObjects() {
    List <sObject>  sobjectList = [SELECT QualifiedApiName FROM EntityDefinition Order by QualifiedApiName];                      
    return sobjectList;
}

In order to access, the fields of the selected sObject, you have to pass the sObject as the parameter.

public static List<FieldDefinition> getFieldOfSobj(String selectedObject){
    List<FieldDefinition> fieldDefinitionList = new List<FieldDefinition>();
    fieldDefinitionList = [SELECT Label,
        DataType,
        QualifiedApiName
        FROM FieldDefinition
        Where EntityDefinition.QualifiedApiName=:selectedObject
    ];
    return fieldDefinitionList;
}

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Lightning Component:

<aura:component controller="selectObjectClass">
 <form>
        <lightning:select class = "slds-select" aura:id = "auraId" value = "{!v.sObject.QualifiedApiName}" label = "Select a sObject:" onchange = "{!c.getSobjField}">
                <aura:iteration items = "{!v.sObject}" var = "obj">
                    <option aura:id="sObj">{!obj.QualifiedApiName}</option>
                </aura:iteration>
            </lightning:select><br/><br/><br/>
<table class="slds-table slds-table_cell-buffer slds-table_bordered"> 
                <thead>
                <tr class="slds-line-height_reset">
                    <th>
                        Action
                    </th>
                    <th>
                        Name
                    </th>                  
                </tr>
                </thead>
                <aura:iteration items="{!v.objField}" var="ob">
                    <tbody>
                    <tr class="slds-hint-parent">
                        <td>
                            <ui:inputCheckbox aura:id="checkFields" value="" text="{!ob.QualifiedApiName}"/>                        </td>
                        <td>
                            {!ob.Label}                            
                        </td>                                               
                    </tr>                            
                    </tbody>
                </aura:iteration>
<thead>
                <tr class="slds-line-height_reset">
                    <th>
                        Action
                    </th>
                    <th>
                        Name
                    </th>                 
                </tr>
                </thead>
                 <aura:iteration items="{!v.objFieldRecords}" var="ob">
                    <tbody>
                    <tr class="slds-hint-parent">
                        <td>
                            <ui:inputCheckbox aura:id="checkFields" value="" text="{!ob.QualifiedApiName}"/>                        </td>
                        <td>
                            {!ob}                            
                        </td>                                               
                    </tr>                            
                    </tbody>
            </table>            
</form>
</aura:component>

Controller:

({
    doInit: function(component, event, helper) {
        helper.selectSobjectt(component, event, helper);
    },
    getSobjField: function(component, event, helper) {
        helper.Fields(component, event, helper);
    },
    handleCheckBoxClick : function(component, event, helper) {
        var selectedFields = [];
        var checkvalue = component.find("checkFields");
        //alert("checkvalue"+checkvalue);
        if(!Array.isArray(checkvalue)){
            if (checkvalue.get("v.value") == true) {
                selectedFields.push(checkvalue.get("v.text"));
            }
        }else{
            for (var i = 0; i < checkvalue.length; i++) {
                if (checkvalue[i].get("v.value") == true) {
                    selectedFields.push(checkvalue[i].get("v.text"));
                }
            }
        }     
        var objectName = component.find("auraId").get("v.value"); 
        component.set("v.selectedFieldValues",selectedFields);
        alert("selectedFields "+selectedFields);  
        alert(component.get("v.selectedFieldValues"));  
        helper.getFieldsRecords(component,event, selectedFields,objectName);        
    },
})

Helper:

selectSobjectt: function(component, event, helper) {
    var action = component.get("c.getsAllObjects");
    action.setCallback(this, function(response) {
        if (response.getState() == "SUCCESS") {
            var value = response.getReturnValue();
            component.set("v.sObject", value);
        }
        else{
            console.log('error'+response.message);
        }
    });
    $A.enqueueAction(action);
},
Fields:function (component,event,helper) {
    try{
        var action = component.get("c.getFieldOfSobj");
        action.setParams({
            "strs":component.find("auraId").get("v.value")
        });
        action.setCallback(this ,function (returnResponse) {
            if(returnResponse.getState() == "SUCCESS"){
                var returnValue = returnResponse.getReturnValue();
                component.set("v.objField",returnValue);
                console.log(returnValue);
            }
            else{
                console.log('error'+returnResponse.message);
            }
        });
        $A.enqueueAction(action);
    }
    catch(ex){
        console.log('ex.message------->'+ex.message);
        }
    },
    getFieldsRecords:function(component, event, selectedFields,objectName){
        var action = component.get("c.getDefaultFieldsRecord");        
        action.setParams({
            "objectName":objectName,
            "fieldObjects":selectedFields
        });
        alert("selectedFields"+selectedFields);
        alert("objectName"+objectName);
        action.setCallback(this,function(response){            
            var state  = response.getState();            
            if(state == "SUCCESS"){
                //alert("1");
                // alert("SUCCESS");
                console.log(response.getReturnValue());                 
                // Set the value in Contact datatable             
                component.set("v.objFieldRecords", response.getReturnValue());
                alert(response.getReturnValue());                
                console.log(response.getReturnValue());
                if(response.getReturnValue().length == 0 && response.getReturnValue()!=null){
                    alert('There are no records');
                }
            }else{                
                // alert("ERROR");
                console.log("Failed with state: " + state);
            }
        });        
        $A.enqueueAction(action);       
    }
})

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Apex Class:

public class selectObjectClass{
    @AuraEnabled
    public static List <sObject> getsAllObjects() {
        List <sObject>  sobjectList = [SELECT QualifiedApiName FROM EntityDefinition Order by QualifiedApiName];                      
        return sobjectList;
    }
    @AuraEnabled
    public static List<FieldDefinition> getFieldOfSobj(String selectedObject){
        List<FieldDefinition> fieldDefinitionList = new List<FieldDefinition>();
        fieldDefinitionList = [SELECT Label,
            DataType,
            QualifiedApiName
            FROM FieldDefinition
            Where EntityDefinition.QualifiedApiName=:selectedObject
        ];
        return fieldDefinitionList;
    }
    @AuraEnabled
    public static List<String> getDefaultFieldsRecord(String objectName, list<String> fieldObjList){
        String strQuery = '';
        String strFieldToQuery = '';
        if( fieldObjList!=null){            
            for(Integer i=0; i < fieldObjList.size()-1;i++){
                strFieldToQuery += fieldObjList[i] + ',';
            }
            strFieldToQuery += fieldObjList[fieldObjList.size()-1];
            strQuery = 'Select ' + strFieldToQuery + ' FROM '+ objectName;
        }
        System.debug('strQuery'+strQuery);
        List<sObject> listOfFieldRecords = Database.query(strQuery);
        System.debug('listOfFieldRecords'+listOfFieldRecords);
        List<String> strData = new List<String>();
        Map<String, Schema.SObjectType> gd = Schema.getGlobalDescribe();
        Schema.SobjectType oType = gd.get(ObjectName);
        for(sObject a: listOfFieldRecords){
            sobject object_instance = oType.newSObject();
            object_instance = a;
            for(String singleField:fieldObjList){
                strData.add((string)object_instance.get(singleField));
            }
        }
        System.debug('strData: = '+strData);
        return strData;        
    }
}