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Rooted TreeA rooted tree G is a connected acyclic graph with a special node that is called the root of the tree and every edge directly or indirectly originates from the root. An ordered rooted tree is a rooted tree where the children of each internal vertex are ordered. If every internal vertex of a rooted tree has not more than m children, it is called an m-ary tree. If every internal vertex of a rooted tree has exactly m children, it is called a full m-ary tree. If m = 2, the rooted tree is called a binary tree.Binary ... Read More
To search within a table of comma-separated values, use LIKE operator. Let us first create a table −mysql> create table DemoTable675(Value text); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable675 values('10, 56, 49484, 93993, 211, 4594'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable675 values('4, 7, 1, 10, 90, 23'); Query OK, 1 row affected (0.41 sec) mysql> insert into DemoTable675 values('90, 854, 56, 89, 10'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable675 values('11, 22, 344, 67, 89'); Query OK, 1 row ... Read More
A relation can be represented using a directed graph.The number of vertices in the graph is equal to the number of elements in the set from which the relation has been defined. For each ordered pair (x, y) in the relation R, there will be a directed edge from the vertex ‘x’ to vertex ‘y’. If there is an ordered pair (x, x), there will be a self- loop on vertex ‘x’.Suppose, there is a relation R = { (1, 1), (1,2), (3, 2) } on set S = { 1, 2, 3 }, it can be represented by the following graph −
Yes, we can name columns in an insert statement. Let us first create a table −mysql> create table DemoTable674( StudentId int, StudentFirstName varchar(100), StudentLastName varchar(100) ); Query OK, 0 rows affected (0.82 sec)Insert some records in the table using insert command −mysql> insert into DemoTable674 set StudentId=10, StudentFirstName='John', StudentLastName='Smith'; Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable674 set StudentId=11, StudentFirstName='Carol', StudentLastName='Taylor'; Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable674 set StudentId=12, StudentFirstName='David', StudentLastName='Miller'; Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable674 set StudentId=13, StudentFirstName='Chris', StudentLastName='Brown'; Query OK, 1 ... Read More
There are mainly two ways to represent a graph −Adjacency MatrixAdjacency ListAdjacency MatrixAn Adjacency Matrix A[V][V] is a 2D array of size V × V where $V$ is the number of vertices in a undirected graph. If there is an edge between Vx to Vy then the value of A[Vx][Vy]=1 and A[Vy][Vx]=1, otherwise the value will be zero. And for a directed graph, if there is an edge between Vx to Vy, then the value of A[Vx][Vy]=1, otherwise the value will be zero.Adjacency Matrix of an Undirected GraphLet us consider the following undirected graph and construct the adjacency matrix −The ... Read More
For this, use GROUP BY HAVING clause. Let us first create a table −mysql> create table DemoTable673( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value int ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable673(Value) values(10); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable673(Value) values(20); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable673(Value) values(10); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable673(Value) values(30); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable673(Value) values(20); Query OK, 1 ... Read More
Relations may exist between objects of the same set or between objects of two or more sets.Definition and PropertiesA binary relation R from set x to y (written as xRy or R(x, y)) is a subset of the Cartesian product x × y. If the ordered pair of G is reversed, the relation also changes.Generally an n-ary relation R between sets A1, ... ,\ and\ An is a subset of the n-ary product A1 × ... × An. The minimum cardinality of a relation R is Zero and the maximum is n2 in this case.A binary relation R on a ... Read More
For this, use order by nullif(). Let us first create a table −mysql> create table DemoTable672( CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY, CustomerName varchar(100), CustomerAmount int ); Query OK, 0 rows affected (0.81 sec)Insert some records in the table using insert command −mysql> insert into DemoTable672(CustomerName, CustomerAmount) values('Chris', 560); Query OK, 1 row affected (0.51 sec) mysql> insert into DemoTable672(CustomerName, CustomerAmount) values('Robert', null); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable672(CustomerName, CustomerAmount) values('', 450); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable672(CustomerName, CustomerAmount) values('David', 456); Query OK, 1 row affected ... Read More
Predicate Calculus deals with predicates, which are propositions containing variables.PredicateA predicate is an expression of one or more variables defined on some specific domain. A predicate with variables can be made a proposition by either assigning a value to the variable or by quantifying the variable.Consider the following statement.Ram is a student.Now consider the above statement in terms of Predicate calculus.Here "is a student" is a predicate and Ram is subject.Let's denote "Ram" as x and "is a student" as a predicate P then we can write the above statement as P(x).Generally a statement expressed by Predicate must have at ... Read More
For particular type of columns beginning with a certain letter, use LIKE. To concatenate the column names, use GROUP_CONCAT() as in the below syntax −SELECT group_concat(COLUMN_NAME separator ' , ') FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = "yourTableName" AND table_schema = "yourDatabaseName" AND column_name LIKE "yourSpecificLetter%";Let us first create a table −mysql> create table DemoTable671( ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ClientName varchar(100), ClientAge int, ClientAddress varchar(200), ClientCountryName varchar(100) ); Query OK, 0 rows affected (0.62 sec)Following is the query to select particular type of columns beginning with a certain letter and fetch all the column ... Read More