SQL Commands Cheat Sheet: Learn with Examples
1. Basic SQL Commands
SELECT
SELECT column1, column2, ... FROM table_name WHERE condition;INSERT
INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...);UPDATE
UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition;DELETE
DELETE FROM table_name WHERE condition;
2. Table Operations
CREATE TABLE
CREATE TABLE table_name ( column1 datatype constraints, column2 datatype constraints, ...);ALTER TABLE
ALTER TABLE table_name ADD column_name datatype;ALTER TABLE table_
C++ Interview Questions and Answers
Ques: 1 can derived clss exception also be caught by the catch block?
Ans:
No
Ques: 2 What Is a B-Tree?
Ans:Read More
The B-tree was invented in 1972 by R. Bayer and E. McCreight, and was designed from the start to create shallow trees for fast disk access. Shallow trees have few �levels�, We have to seek through them fewer times, and therefore they run quickly. Because seeks often require going to disk for the information we need, The performance increase with a shallow tree rather than a deeper
Hydraulic Systems Components and Operation
1) Basic Components of a Pond and Their Functions
1. Vent: Since the oil inside the tank comes and goes, you need a vent to allow air to enter or exit when the oil level changes, preventing a vacuum.
2. Oil Level: The level indicator is used to verify the current oil volume in the tank, which should ideally be twice the amount used by the circuit.
3. Thermometer: This checks the oil temperature in the reservoir, as each type of oil has specific operating temperature limits.
4. Oil Output: This is where
Read MoreMetal Casting, Silverware, and Pottery Techniques
Metal Casting
Casting of Metals
Iron, known for its hardness and elasticity, cannot be worked directly (it requires rolling and merging). Various techniques are employed to create sculptures, including building (shaping iron with fire and a hammer). Two primary methods exist:
- Direct (forging, spinning): Striking hot or cold rods.
- Casting: Notably, the Lost Wax Technique.
Welding
Welding involves melting using an iron electrode on both surfaces, resulting in a strong and rigid union. Welding by contribution
Read MoreC++ Interview Questions and Answers: A Comprehensive Guide
Ques: 1 can derived clss exception also be caught by the catch block?
Ans:
No
Ques: 2 What Is a B-Tree?
Ans:Read More
The B-tree was invented in 1972 by R. Bayer and E. McCreight, and was designed from the start to create shallow trees for fast disk access. Shallow trees have few �levels�, We have to seek through them fewer times, and therefore they run quickly. Because seeks often require going to disk for the information we need, The performance increase with a shallow tree rather than a deeper
Refrigeration Systems and Refrigerants: A Comprehensive Guide
1. Refrigerants
1.1 Definition
Refrigerant is a fluid used in heat transfer within a refrigeration system. It absorbs heat at low temperature and pressure.
1.2 Designation of Refrigerants
Refrigerants are identified by their chemical formula, name, or a numerical symbolic name when necessary.
2. Refrigerating Fluids (Secondary Refrigerants)
2.1 Definition
A substance used to extract heat by increasing its sensible heat (e.g., brine).
3. Classification of Locations
3.1 Institutional Locations
These are locations
Read More