What is the difference between count 1 and count (*) in a sql query?

0 Answers  

---

what is try_catch block in procedure

0 Answers  

---

How to perform a loop through all tables in pl/sql?

4 Answers   Evosys, MBT,

---

How do we tune the code?

2 Answers  

---

How to create an array in pl/sql?

0 Answers  

---

---

how are rank and dense rank being alloted for column with same values over a particular column

1 Answers  

---

Why having clause is used in sql?

0 Answers  

---

Can sql developer connect to db2?

0 Answers  

---

What does select count (*) mean in sql?

0 Answers  

---

SELECT emp_num, years, SUM(salary) FROM sales UNION ALL SELECT emp_id, SUM(takehomepay) FROM marketing What error is present in the sample code above? 1. Queries being combined with the UNION ALL statement are not allowed to have SELECT lists with a different number of expressions. 2. You are not allowed to use aggregate functions within two queries joined by a UNION ALL statement. 3. The UNION ALL statement incorrectly combines the "years" result from the first query with the "SUM (takehomepay)" result from the second query. 4. Unless the UNION ALL statement is replaced with a UNION statement, the queries will return duplicates. 5. The "emp_id" column from the second query must be renamed (or aliased) as "emp_num" so that it corresponds to the column name from the first query. Otherwise, the queries will not execute.

3 Answers  

---

What is a nested table in word?

0 Answers  

---

What is a natural join sql?

0 Answers  

---