Answer / Manoj Singh

A constraint in SQL and PL/SQL is a rule that is used to enforce integrity of data in a database. It ensures the validity of data by enforcing rules such as uniqueness, referential integrity, null values etc. Some common types of constraints include PRIMARY KEY, FOREIGN KEY, UNIQUE, CHECK, and NOT NULL.

What is union?

1 Answers  

---

Is sql better than excel?

1 Answers  

---

why should required nested tables, Object types, partition tables and varying arrays. what is the difference between these are all. give me example with explanation.

2 Answers  

---

What is nvl?

1 Answers  

---

What is the size of partition table?

1 Answers  

---

What is meant by Join? What are the different types of Joins available? Explain.

5 Answers   Cap Gemini,

---

How do you explain an index?

1 Answers  

---

How do you take the union of two tables in sql?

1 Answers  

---

How to look at the current sql*plus system settings?

1 Answers  

---

Which is the correct statement about truncate and delete?

1 Answers  

---

What is data profiling in sql?

1 Answers  

---

What is trigger and types?

1 Answers  

---