MongoDB Query Operators Part-2 Element Query Operator This operator is used to find the documents based on the datatypes and the fields in a document. There are two element query operators. 1. exists ($exists) 2. type ($type) 1. exist ($exist): This operator is used to… Read More
Clauses and filters: Like clause:
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college=# select * from report where temp_hi:: text like '4%'; place | temp_lo | temp_hi | date | humidity | precp ----------------------------------------------------------- VZG | 32 | 43 | 2023-05-10 | 21 | HYD | 32 | 43 | 2020-07-19 | 24 | BZA | 32 | 43 | 2023-05-09 | 23 | (3 rows) |
LIMIT Clause: The LIMIT clause is used to restrict the number of rows returned in the result set. It is useful when you want to retrieve only a certain number of rows.
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college=# select * from report LIMIT 4; place | temp_lo | temp_hi | date | humidity | precp ----------------------------------------------------------- VZG | 32 | 43 | 2023-05-10 | 21 | HYD | 32 | 43 | 2020-07-19 | 24 | BZA | 32 | 43 | 2023-05-09 | 23 | Delhi | 23 | 34 | 2023-05-15 | 24 | (4 rows) |
OFFSET Clause: It is used in conjunction… Read More
JOIN OPERATION IN PostgreSQL: In PostgreSQL, the JOIN clause is used to combine rows from two or more tables based on a related column or condition. It specifies how the tables should be joined and on which columns the join should be performed. There are… Read More
MongoDB Query Operators There are different types of Operators available in MongoDB which are used to filter the data. 1 – Comparison operators 2 – Logical operators 3 – Element operators 4 – Evaluation operators 5 – Geospatial operators 6 – Array operators 7 –… Read More
In PostgreSQL, “ALTER” and “UPDATE” are two different SQL commands used to modify data in a database. “ALTER” is used to modify the structure of the database, while “UPDATE” is used to modify the data stored within the database. Update: The UPDATE command plays a… Read More
MongoDB CRUD Operations 1 – To create a new database called sample data. Atlas atlas-dsrabt-shard-0 [primary] myFirstDatabase> use sample data. 2 – To create a new collection called students. Atlas atlas-dsrabt-shard-0 [primary] sampledata> db.createCollection(“students”). 3 – To insert one document in to the collection called… Read More
CREATING A NEW TABLE You can create a new table by specifying the table name, along with all column names and their types. Syntax for table creation: CREATE TABLE table_name( column1 datatype, column2 datatype, column3 datatype, columnN datatype, PRIMARY KEY (one or more columns) ); An example for creating table on weather… Read More
Basic MongoDB Commands Operations 👉👉👉Please check the below video 1 – To shows all the databases Atlas atlas-dsrabt-shard-0 [primary] myFirstDatabase> show dbs 2 – To use the database called sample_airbnb Atlas atlas-dsrabt-shard-0 [primary] myFirstDatabase> use sample_airbnb 3 – To show all the collections in… Read More
Installation of PostgreSQL Through YUM & RPM Methods These are another two methods of installation of PostgreSQL in Linux systems: 1 – YUM Installation. 2 – RPM Installation Installation of PostgreSQL through YUM package manager in Linux System: If you are using a Linux system,… Read More
Installation Of Robo 3T On Windows Robo 3T: Robo 3T is a free and open-source MongoDB GUI tool that allows users to manage their MongoDB databases with ease. Robo 3T provides features such as code autocompletion, a built-in query editor, and the ability to save… Read More
