---
title: "SQL Queries"  
description: "In previous article we have discussed about SQL and some queries. In this part we will continue on SQL Queries:  Customer IdNameAddressContact   Marks"  
author: "Samuel Fernandes"  
published: 2016-06-30  
updated: 2018-03-16  
canonical: https://www.mindstick.com/blog/11169/sql-queries  
category: "mysql"  
tags: ["database", "sql"]  
reading_time: 10 minutes  

---

# SQL Queries

In previous article we have discussed about [SQL](https://www.mindstick.com/blog/11168/introduction-to-sql) and some queries. In this part we will continue on [SQL Queries](https://www.mindstick.com/forum/159818/how-to-use-the-coalesce-function-to-handle-null-values-in-sql-queries):\

| \| ## Customer Id \| ## Name \| ## Address \| ## Contact Marks \| \| --- \| --- \| --- \| --- \| \| 12ST09 \| John \| USA \| 456788 54 \| \| 12ST10 \| Royce \| Argentina \| 457912 34 \| \| 12ST11 \| Mickel \| London \| 56276 45 \| \| 12ST12 \| Tom \| New york \| 2898938 43 \| \| 12ST13 \| Hugh \| Luanda \| 2974789 37 \| \| 12ST14 \| Nolan \| Paris \| 232688 56 \| \| 12ST15 \| Jennifer \| USA \| 43762762 67 \| |  |  |  |
| --- | --- | --- | --- |
| ## Customer Id | ## Name | ## Address | ## Contact Marks |
| 12ST09 | John | USA | 456788 54 |
| 12ST10 | Royce | Argentina | 457912 34 |
| 12ST11 | Mickel | London | 56276 45 |
| 12ST12 | Tom | New york | 2898938 43 |
| 12ST13 | Hugh | Luanda | 2974789 37 |
| 12ST14 | Nolan | Paris | 232688 56 |
| 12ST15 | Jennifer | USA | 43762762 67 |

## BETWEEN

**BETWEEN** operator is used to select values within a range. These values can be numbers, text, or dates.

**Syntax**

```
SELECT column_name
FROM name_of_table
WHERE column_name BETWEEN value1 AND value2;
SELECT column_name
FROM name_of_table
WHERE column_name BETWEEN value1 AND value2;
SELECT column_name
FROM name_of_table
WHERE column_name BETWEEN value1 AND value2;
```

Example:

```
SELECT * FROM student_info
WHERE marks BETWEEN 30 AND 40;
```

\

Output:

| \| 12ST10 \| Royce \| Argentina \| 457912 34 \| \| \| \| \| \| --- \| --- \| --- \| --- \| --- \| --- \| --- \| --- \| \| 12ST13 \| Hugh \| Luanda \| 237644 37 \| \| \| \| \| \| \| \| \| \| \| \| \| \| |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 12ST10 | Royce | Argentina | 457912 34 |  |  |  |  |
| 12ST13 | Hugh | Luanda | 237644 37 |  |  |  |  |
|  |  |  |  |  |  |  |  |

**Aliases**

**Aliases** are used to give temporary name to [database table](https://www.mindstick.com/forum/159366/how-to-test-regular-expressions-in-sql-without-using-database-table) or a column in a table. Basically SQL aliases are created to make database table more readable. Following is the syntax of aliases:

**Syntax:**

For column

```
SELECT column_name AS name_of_alias
FROM name_of_table;
```

**Syntax:**

For table

```
SELECT column_name
FROM name_of_table AS name_of_alias;
```

## Example:

```
SELECT name AS Firstname,
FROM student_info;
```

## Output:

| \| ## Firstname \| \| --- \| \| John \| \| Royce \| \| Mickel \| \| Tom \| \| Hugh \| \| Nolan \| \| Jennifer \| |
| --- |
| ## Firstname |
| John |
| Royce |
| Mickel |
| Tom |
| Hugh |
| Nolan |
| Jennifer |

**JOIN**

**JOIN** clause is used to combine rows from two or more rows, based on common column between them. The most common type is [INNER JOIN](https://www.mindstick.com/forum/33572/sql-inner-join-keyword) which returns all rows from tables where the join condition is met.

Here are two tables:

**[Student table](https://www.mindstick.com/forum/157561/what-is-the-stored-procedure-create-a-procedure-to-find-the-record-by-stu_id-from-the-student-table)**

| \| ## studentId \| ## Name \| ## Address \| \| --- \| --- \| --- \| \| 12ST09 \| John \| USA \| \| 12ST10 \| Royce \| Argentina \| \| 12ST11 \| Mickel \| London \| \| 12ST12 \| Tom \| New york \| \| 12ST13 \| Hugh \| Luanda \| \| 12ST14 \| Nolan \| Paris \| \| 12ST15 \| Jennifer \| USA \| |  |  |
| --- | --- | --- |
| ## studentId | ## Name | ## Address |
| 12ST09 | John | USA |
| 12ST10 | Royce | Argentina |
| 12ST11 | Mickel | London |
| 12ST12 | Tom | New york |
| 12ST13 | Hugh | Luanda |
| 12ST14 | Nolan | Paris |
| 12ST15 | Jennifer | USA |

**Marks table**

| \| ## studentId \| ## Contact Marks \| \| --- \| --- \| \| 12ST09 \| 456788 54 \| \| 12ST10 \| 457912 34 \| \| 12ST11 \| 56276 45 \| \| 12ST12 \| 2898938 43 \| \| 12ST13 \| 2974789 37 \| \| 12ST14 \| 232688 56 \| \| 12ST15 \| 43762762 67 \| |  |
| --- | --- |
| ## studentId | ## Contact Marks |
| 12ST09 | 456788 54 |
| 12ST10 | 457912 34 |
| 12ST11 | 56276 45 |
| 12ST12 | 2898938 43 |
| 12ST13 | 2974789 37 |
| 12ST14 | 232688 56 |
| 12ST15 | 43762762 67 |

```
SELECT student.name, student.contact,marks.marks
FROM student
INNER JOIN marks
ON student.studentId=marks.studentId;
```

**Output:**

| \| ## Name \| ## Contact Marks \| \| --- \| --- \| \| John \| 456788 54 \| \| Royce \| 457912 34 \| \| Mickel \| 56276 45 \| \| Tom \| 2898938 43 \| \| Hugh \| 2974789 37 \| \| Nolan \| 232688 56 \| \| Jennifer \| 43762762 67 \| |  |
| --- | --- |
| ## Name | ## Contact Marks |
| John | 456788 54 |
| Royce | 457912 34 |
| Mickel | 56276 45 |
| Tom | 2898938 43 |
| Hugh | 2974789 37 |
| Nolan | 232688 56 |
| Jennifer | 43762762 67 |

**LEFT JOIN**

The **LEFT** JOIN keyword returns all the rows from first table, with the matching rows in the second table. NULL result will be shown if there is no match

**Syntax:**

```
SELECT column_name
FROM tablefirst
LEFT JOIN tablesecond
ON tablefirst.column_name=tablesecond.column_name;
```

##### Example:

```
SELECT student.name, marks.studentId
FROM student
LEFT JOIN marks
ON student.studentId=marks.studentId;
```

## Output:

| \| ## Name \| ## studentId \| \| --- \| --- \| \| John \| 12ST09 \| \| Royce \| 12ST10 \| \| Mickel \| 12ST11 \| \| Tom \| 12ST12 \| \| Hugh \| 12ST13 \| \| Nolan \| 12ST14 \| \| Jennifer \| 12ST15 \| |  |
| --- | --- |
| ## Name | ## studentId |
| John | 12ST09 |
| Royce | 12ST10 |
| Mickel | 12ST11 |
| Tom | 12ST12 |
| Hugh | 12ST13 |
| Nolan | 12ST14 |
| Jennifer | 12ST15 |

**RIGHT JOIN**

**RIGHT JOIN** keyword return all rows from second table, with the matching rows in first table. Null is return if there is no match found.

**Syntax:**

```
SELECT column_name
FROM tablefirst
RIGHT JOIN tablesecond
ON tablefirst.column_name=tablesecond.column_name;
```

##### Example:

```
SELECT marks.studentId, student.name
FROM marks
RIGHT JOIN student
ON marks.studentId=student.studentId;
```

## Output:

| \| ## studentId \| ## Name \| \| --- \| --- \| \| 12ST09 \| John \| \| 12ST10 \| Royce \| \| 12ST11 \| Mickel \| \| 12ST12 \| Tom \| \| 12ST13 \| Hugh \| \| 12ST14 \| Nolan \| \| 12ST15 \| Jennifer \| |  |
| --- | --- |
| ## studentId | ## Name |
| 12ST09 | John |
| 12ST10 | Royce |
| 12ST11 | Mickel |
| 12ST12 | Tom |
| 12ST13 | Hugh |
| 12ST14 | Nolan |
| 12ST15 | Jennifer |

**[FULL OUTER JOIN](https://www.mindstick.com/forum/1216/full-outer-join-on-2-data-tables-with-a-list-of-columns)**

The **FULL OUTER JOIN** will return all rows from first table and all rows from second table. The FULL OUTER JOIN is the result of both LEFT and RIGHT joins.

**Syntax:**

```
SELECT column_name
FROM tablefirst
FULL OUTER JOIN tablesecond
ON tablefirst.column_name=tablesecond.column_name;
```

##### Example:

```
SELECT student.studentname, marks.studentId
FROM student
FULL OUTER JOIN marks
ON student.studentId=marks.studentId;
```

#####

**Output:**

| \| ## Name \| ## studentId \| \| --- \| --- \| \| John \| 12ST09 \| \| Royce \| 12ST10 \| \| Mickel \| 12ST11 \| \| Tom \| 12ST12 \| \| Hugh \| 12ST13 \| \| Nolan \| 12ST14 \| \| Jennifer \| 12ST15 \| |  |
| --- | --- |
| ## Name | ## studentId |
| John | 12ST09 |
| Royce | 12ST10 |
| Mickel | 12ST11 |
| Tom | 12ST12 |
| Hugh | 12ST13 |
| Nolan | 12ST14 |
| Jennifer | 12ST15 |

**UNION**

The **UNION** operator is used to combine the result of two or more SELECT statements. Please note [SELECT statement](https://www.mindstick.com/forum/160076/explain-the-sql-select-statement-and-how-it-s-used-to-search-for-data-in-a-database) with in the union must have same number of column.

**Syntax:**

SELECT column_name FROM tablefirst UNION SELECT column_name FROM tablesecond;

##### Example:

```
SELECT name FROM student
UNION
SELECT contact,marks FROM marks;
```

##### Output:

| \| ## Name \| ## Contact Marks \| \| --- \| --- \| \| John \| 456788 54 \| \| Royce \| 457912 34 \| \| Mickel \| 56276 45 \| \| Tom \| 2898938 43 \| \| Hugh \| 2974789 37 \| \| Nolan \| 232688 56 \| \| Jennifer \| 43762762 67 \| |  |
| --- | --- |
| ## Name | ## Contact Marks |
| John | 456788 54 |
| Royce | 457912 34 |
| Mickel | 56276 45 |
| Tom | 2898938 43 |
| Hugh | 2974789 37 |
| Nolan | 232688 56 |
| Jennifer | 43762762 67 |

## SELECT INTO

The **SELECT INTO** statement select [record from one](https://www.mindstick.com/articles/12549/show-gridview-record-from-one-form-to-another-form) table and insert into another table. Following is the syntax of SELECT INTO:

```
SELECT *
INTO new table
FROM tablefirst;
```

Or we can insert one column

```
SELECT column_name
INTO new table [IN externaldb]
FROM tablefirst;
 
```

##### INSERT INTO SELECT

The **[INSERT INTO SELECT](https://www.mindstick.com/interview/23338/the-sql-insert-into-select-statement)** statement selects data from one table and inserts it into an [existing table](https://www.mindstick.com/forum/157761/how-to-add-a-column-with-a-default-value-to-an-existing-table-in-sql-server). Following is the example of INSERT INTO SELECT:

**Syntax:**

```
INSERT INTO tablesecond
SELECT * FROM tablefirst;
```

##### Example:

```
INSERT INTO student
SELECT * FROM marks;
```

## Output:

| \| ## Customer Id \| ## Name \| ## Address \| ## Contact Marks \| \| --- \| --- \| --- \| --- \| \| 12ST09 \| John \| USA \| 456788 54 \| \| 12ST10 \| Royce \| Argentina \| 457912 34 \| \| 12ST11 \| Mickel \| London \| 56276 45 \| \| 12ST12 \| Tom \| New york \| 2898938 43 \| \| 12ST13 \| Hugh \| Luanda \| 2974789 37 \| \| 12ST14 \| Nolan \| Paris \| 232688 56 \| \| 12ST15 \| Jennifer \| USA \| 43762762 67 \| |  |  |  |
| --- | --- | --- | --- |
| ## Customer Id | ## Name | ## Address | ## Contact Marks |
| 12ST09 | John | USA | 456788 54 |
| 12ST10 | Royce | Argentina | 457912 34 |
| 12ST11 | Mickel | London | 56276 45 |
| 12ST12 | Tom | New york | 2898938 43 |
| 12ST13 | Hugh | Luanda | 2974789 37 |
| 12ST14 | Nolan | Paris | 232688 56 |
| 12ST15 | Jennifer | USA | 43762762 67 |

---

Original Source: https://www.mindstick.com/blog/11169/sql-queries

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