To convert bool to int in MySQL, you can use CAST(). Let us first create a table:mysql> create table convertBoolToIntDemo -> ( -> isYoung bool -> ); Query OK, 0 rows affected (0.69 sec)Following is the query to insert some records ... Read More

To get total number of fields in all tables in database, you can use information_schema.columns along with aggregate function count(*).We are using ‘sample’ database which consists of a lot of tables with fields. Following is the query to get total number of fields in all tables in database:mysql> SELECT COUNT(*) ... Read More

The IntStream class in Java the following two forms of of() methodIntStream of(int t) methodThe following of() method returns a sequential IntStream containing a single element. Here is the syntaxstatic IntStream of(int t)Here, parameter t is the single element.IntStream of(int… values) methodThe following of() method returns a sequentially ordered stream ... Read More

The maxBy() method of the Collectors class in Java 8 returns a Collector that produces the maximal element according to a given Comparator, described as an Optional.The syntax is as followsstatic Collector maxBy(Comparator

To change a primary key to auto_increment, you can use MODIFY command. Let us first create a table.mysql> create table changePrimaryKeyInAutoIncrement    -> (    -> StudentId int not null primary key,    -> StudentName varchar(100),    -> StudentAge int,    -> StudentAddress varchar(100)    -> ); Query OK, 0 ... Read More

To increment a value in nested object, you can use $inc operator. Let us first implement the following query to create a collection with documents>db.incrementValueDemo.insertOne({"StudentName":"Larry", "StudentCountryName":"US", "StudentDetails":[{"StudentSubjectName":"Math", "StudentMathMarks":79}]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c986ca0330fd0aa0d2fe4a2") }Following is the query to display all documents from a collection with the ... Read More

To count value for multiple columns, use the CASE statement. Let us first create a table::mysql> create table countValueMultipleColumnsDemo    -> (    -> Value1 int,    -> Value2 int,    -> Value3 int    -> ); Query OK, 0 rows affected (0.62 sec)Following is the query to insert some ... Read More

In MySQL, AUTO_INCREMENT=3 tells that the inserted record will start from 3 not the default 1. Let us first create a sample table and set auto increment to 3:mysql> create table Auto_incrementDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(20)    -> ... Read More

Yes, you can concatenate strings with || in MySQL with the help of sql_mode. Set the sql_mode to PIPES_AS_CONCAT.The syntax is as followsset sql_mode=PIPES_AS_CONCAT;The following is the syntax to concat with the help of ||.SELECT ‘yourValue' || yourColumName AS anyAliasName FROM yourTableName;To understand the above syntax, let us create a ... Read More

To select one specific row and another random row, you can use ORDER BY and RAND(). Let us first create a sample table:mysql> create table oneSpecificRowAndOtherRandom    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(20)    -> ); Query OK, 0 rows affected ... Read More