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There are lots of options available to replace NULL values using select statement. You can use CASE statement or IFNULL() or COALESCE()Case 1 − Using IFNULL()The syntax of IFNULL() is as follows −SELECT IFNULL(yourColumnName, ’yourValue’) AS anyVariableName from yourTableName;Case 2 − Using COALESCE()The syntax of COALESCE() is as follows −SELECT COALESCE(yourColumnName, ’yourValue’) AS anyVariableName from yourTableName;Case 3 − Using CASE statementThe syntax of CASE statement.SELECT CASE WHEN yourColumnName IS NULL THEN ‘yourValue’ ELSE yourColumnName END AS anyVariableName FROM yourTableNameTo understand what we discussed above, let us create a table. The query to create a table is as follows −mysql> create ... Read More
To update for _id, use $set in MongoDB. Let us create a collection with documents −db.demo741.insertOne({SubjectName:"MySQL"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead718657bb72a10bcf0672") } > db.demo741.insertOne({SubjectName:"C"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead718957bb72a10bcf0673") } > db.demo741.insertOne({SubjectName:"Java"}); { "acknowledged" : true, "insertedId" : ObjectId("5ead718e57bb72a10bcf0674") }Display all documents from a collection with the help of find() method −> db.demo741.find();This will produce the following output −{ "_id" : ObjectId("5ead718657bb72a10bcf0672"), "SubjectName" : "MySQL" } { "_id" : ObjectId("5ead718957bb72a10bcf0673"), "SubjectName" : "C" } { "_id" : ObjectId("5ead718e57bb72a10bcf0674"), "SubjectName" : "Java" }Following is the query to updating MongoDB for _id ... Read More
Let us create a collection with documents −> db.demo740.insertOne({ ... "details": ... [ ... { ... Name:"Chris", ... Age:21, ... CountryName:"US" ... }, ... { ... Name:"Bob", ... Age:20, ... CountryName:"UK", ... isMarried:true ... } ... ] ... }); { "acknowledged" : true, "insertedId" : ObjectId("5ead700c57bb72a10bcf066d") }Display all documents from a collection with the help ... Read More
To update an entire row in MySQL, use UPDATE command. You need to know the primary key column. The syntax is as follows to update an entire row.UPDATE yourTableName SET yourColumnName1 = ’yourValue1’ ,yourColumnName2 = ’yourValue2’ , yourColumnName3 = ’yourValue3’ ,.......................N WHERE yourPrimaryKeyColumnName = yourValue;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table UpdateEntireRowDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(20), -> Age int, -> Marks int, -> PRIMARY KEY(Id) -> ); Query OK, ... Read More
Use the rotateZ(angle) method to rotate transform the element by using z-axis with CSS3 −ExampleLive Demo div { width: 200px; height: 100px; background-color: pink; border: 1px solid black; } div#zDiv { -webkit-transform: rotateZ(90deg); /* Safari */ transform: rotateZ(90deg); /* Standard syntax */ } rotate Z axis tutorials point.com. Output
To push value, use save() along with for loop. Let us create a collection with documents −> for(var v=1; v db.demo739.find();This will produce the following output −{ "_id" : ObjectId("5ead6e7857bb72a10bcf0666"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf0667"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf0668"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf0669"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf066a"), "Name" : "Chris", "SubjectName" : "MongoDB" } { "_id" : ObjectId("5ead6e7857bb72a10bcf066b"), "Name" : "Chris", "SubjectName" : "MongoDB" }
You can count values from comma-separated field using CHAR_LENGTH() method from MySQL. The syntax is as follows −SELECT *, (CHAR_LENGTH(yourColumnName) - CHAR_LENGTH(REPLACE(yourColumnName, ', ', '')) + 1) as anyVariableName from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table CountValuesCommaSeparated -> ( -> Id int NOT NULL AUTO_INCREMENT, -> CommaSeparatedValue text, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (1.76 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into CountValuesCommaSeparated(CommaSeparatedValue) values('101, 104, ... Read More
Let us create a collection with documents −> db.demo738.insertOne({Subjects:["C", "C++"]}); { "acknowledged" : true, "insertedId" : ObjectId("5ead696557bb72a10bcf0661") } > db.demo738.insertOne({Subjects:["MySQL", "PL/SQL"]}); { "acknowledged" : true, "insertedId" : ObjectId("5ead696657bb72a10bcf0662") }Display all documents from a collection with the help of find() method −> db.demo738.find();This will produce the following output −{ "_id" : ObjectId("5ead696557bb72a10bcf0661"), "Subjects" : [ "C", "C++" ] } { "_id" : ObjectId("5ead696657bb72a10bcf0662"), "Subjects" : [ "MySQL", "PL/SQL" ] }Following is the query to push −>db.demo738.update({_id:ObjectId("5ead696657bb72a10bcf0662")}, {$push:{"Subjects":"MongoDB"}}); WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })Display all documents from a collection with the help of ... Read More
Use the background-repeat property to display the background image only once. You can try to run the following code to implement the background-repeat property −ExampleLive Demo body { background-image: url("https://www.tutorialspoint.com/videotutorials/images/tutor_connect_home.jpg"); background-repeat: no-repeat; } Background Image
To order by timestamp, use sort() in MongoDB. Let us create a collection with documents −> db.demo737.insertOne({"timestamp" : new ISODate("2020-04-01" )}); { "acknowledged" : true, "insertedId" : ObjectId("5ead682157bb72a10bcf065c") } > db.demo737.insertOne({"timestamp" : new ISODate("2020-10-31" )}); { "acknowledged" : true, "insertedId" : ObjectId("5ead682757bb72a10bcf065d") } > db.demo737.insertOne({"timestamp" : new ISODate("2020-05-02" )}); { "acknowledged" : true, "insertedId" : ObjectId("5ead682a57bb72a10bcf065e") }Display all documents from a collection with the help of find() method −> db.demo737.find();This will produce the following output −{ "_id" : ObjectId("5ead682157bb72a10bcf065c"), "timestamp" : ISODate("2020-04-01T00:00:00Z") } { "_id" : ObjectId("5ead682757bb72a10bcf065d"), "timestamp" : ISODate("2020-10-31T00:00:00Z") } { "_id" : ... Read More