INSERT INTO multiple rows in SQL - Step-by-Step Execution

Concept Flow - INSERT INTO multiple rows

Start INSERT

↓

Specify Table

↓

List Columns

↓

Provide Multiple Rows Values

↓

Execute Insert

↓

Rows Added to Table

↓

End

This flow shows how SQL inserts multiple rows into a table by specifying the table, columns, and multiple sets of values.

Execution Sample

SQL

INSERT INTO students (id, name) VALUES
(1, 'Alice'),
(2, 'Bob'),
(3, 'Charlie');

This SQL command inserts three rows into the 'students' table with id and name values.

Execution Table

Step	Action	Values Inserted	Table State After Step
1	Start INSERT INTO students	None	Empty table
2	Specify columns (id, name)	None	Empty table
3	Insert row 1	(1, 'Alice')	[{id:1, name:'Alice'}]
4	Insert row 2	(2, 'Bob')	[{id:1, name:'Alice'}, {id:2, name:'Bob'}]
5	Insert row 3	(3, 'Charlie')	[{id:1, name:'Alice'}, {id:2, name:'Bob'}, {id:3, name:'Charlie'}]
6	End INSERT	All rows inserted	Table has 3 new rows

💡 All specified rows inserted successfully into the table.

Variable Tracker

Variable	Start	After 1	After 2	After 3	Final
table_rows	[]	[{id:1, name:'Alice'}]	[{id:1, name:'Alice'}, {id:2, name:'Bob'}]	[{id:1, name:'Alice'}, {id:2, name:'Bob'}, {id:3, name:'Charlie'}]	[{id:1, name:'Alice'}, {id:2, name:'Bob'}, {id:3, name:'Charlie'}]

Key Moments - 2 Insights

Why do we list multiple sets of values separated by commas?

Each set of values inside parentheses represents one row to insert. Commas separate these rows, as shown in execution_table steps 3 to 5.

What happens if the number of values doesn't match the number of columns?

The SQL engine will give an error because each row must have the same number of values as the columns listed, as implied in step 2 and 3 of the execution_table.

Visual Quiz - 3 Questions

Look at the execution_table, what is the table state after step 4?

A [{id:1, name:'Alice'}]

B [{id:1, name:'Alice'}, {id:2, name:'Bob'}]

C [{id:1, name:'Alice'}, {id:3, name:'Charlie'}]

D Empty table

💡 Hint

Check the 'Table State After Step' column for step 4 in execution_table.

At which step are all rows inserted into the table?

A Step 6

B Step 5

C Step 3

D Step 2

💡 Hint

Look at the 'Action' and 'Table State After Step' columns in execution_table for the final insertion.

If we add a fourth row, how would variable 'table_rows' change after that insertion?

A It stays the same as after step 3

B It removes the first row

C It adds the new row to the list

D It becomes empty

💡 Hint

Refer to variable_tracker row 'table_rows' and see how it grows after each insertion.

Concept Snapshot

INSERT INTO table_name (columns) VALUES
(row1_values), (row2_values), ...;
- Inserts multiple rows in one command
- Each row's values in parentheses, separated by commas
- Number of values must match columns
- Efficient way to add many rows at once

Full Transcript

This visual execution shows how the SQL INSERT INTO command adds multiple rows to a table. First, the table and columns are specified. Then, multiple sets of values are provided, each representing one row. Each row is inserted step-by-step, updating the table state. The process ends when all rows are added. Key points include matching values to columns and separating rows by commas.

Practice

1. What does the SQL statement INSERT INTO table_name (col1, col2) VALUES (1, 'A'), (2, 'B'); do?

easy

A. Deletes rows where col1 is 1 or 2.

B. Updates existing rows with new values.

C. Inserts two new rows into the table with specified values.

D. Creates a new table named table_name.

Solution

1. Step 1: Understand the INSERT INTO syntax

   The statement specifies columns and multiple sets of values separated by commas.

2. Step 2: Recognize the effect of multiple value sets

   Each set of values adds one new row to the table.

3. Final Answer:

   Inserts two new rows into the table with specified values. -> Option C

4. Quick Check:

   Multiple VALUES sets = multiple rows inserted [OK]

Hint: Multiple VALUES sets add multiple rows at once [OK]

Common Mistakes:

• Thinking it updates rows instead of inserting
• Confusing INSERT with DELETE or UPDATE
• Believing it creates a new table

2. Which of the following is the correct syntax to insert multiple rows into a table named students with columns id and name?

easy

A. INSERT INTO students (id, name) SET (1, 'Alice'), (2, 'Bob');

B. INSERT INTO students (id, name) VALUES (1, 'Alice'), (2, 'Bob');

C. INSERT INTO students (id, name) VALUES (1, 'Alice') AND (2, 'Bob');

D. INSERT INTO students VALUES (1, 'Alice'); (2, 'Bob');

Solution

1. Step 1: Check the correct use of VALUES keyword

   VALUES keyword must be followed by multiple sets of values separated by commas.

2. Step 2: Identify correct punctuation and keywords

   INSERT INTO students (id, name) VALUES (1, 'Alice'), (2, 'Bob'); uses commas correctly and no extra keywords like AND or SET.

3. Final Answer:

   INSERT INTO students (id, name) VALUES (1, 'Alice'), (2, 'Bob'); -> Option B

4. Quick Check:

   VALUES + comma-separated tuples = correct syntax [OK]

Hint: Use VALUES with comma-separated rows, no AND or SET [OK]

Common Mistakes:

• Using semicolons between value sets
• Using AND instead of commas
• Using SET keyword incorrectly

3. Given the table products(id INT, name VARCHAR(20)), what will be the result of this query?

INSERT INTO products (id, name) VALUES (1, 'Pen'), (2, 'Pencil'), (3, 'Eraser');
SELECT * FROM products;

medium

A. No rows will be added because SELECT does not insert data.

B. Only one row with id 3 and name Eraser will be added.

C. The query will cause a syntax error.

D. Three new rows with ids 1, 2, 3 and names Pen, Pencil, Eraser will be added.

Solution

1. Step 1: Analyze the INSERT statement

   The INSERT adds three rows with given ids and names in one command.

2. Step 2: Understand the SELECT statement

   SELECT * FROM products will show all rows including the newly inserted ones.

3. Final Answer:

   Three new rows with ids 1, 2, 3 and names Pen, Pencil, Eraser will be added. -> Option D

4. Quick Check:

   Multiple VALUES sets insert multiple rows [OK]

Hint: INSERT adds all rows; SELECT shows them all [OK]

Common Mistakes:

• Thinking only last row inserts
• Confusing SELECT with INSERT
• Expecting syntax error due to multiple rows

4. Identify the error in this SQL statement:

INSERT INTO employees (id, name) VALUES (1, 'John'); (2, 'Jane');

medium

A. Using semicolon between value sets causes syntax error.

B. Missing column names in the statement.

C. VALUES keyword is missing.

D. Using single quotes around names is invalid.

Solution

1. Step 1: Check punctuation between value sets

   Multiple rows must be separated by commas, not semicolons.

2. Step 2: Confirm correct use of VALUES and quotes

   VALUES keyword is present and single quotes for strings are correct.

3. Final Answer:

   Using semicolon between value sets causes syntax error. -> Option A

4. Quick Check:

   Use commas, not semicolons, between multiple VALUES [OK]

Hint: Separate multiple rows with commas, not semicolons [OK]

Common Mistakes:

• Using semicolons instead of commas
• Omitting column list when required
• Misusing quotes around strings

5. You want to insert multiple rows into a table orders(order_id, product, quantity) but only have values for product and quantity. Which query correctly inserts three rows with products and quantities, letting order_id auto-increment?

hard

A. INSERT INTO orders (product, quantity) VALUES ('Book', 2), ('Pen', 5), ('Notebook', 3);

B. INSERT INTO orders VALUES ('Book', 2), ('Pen', 5), ('Notebook', 3);

C. INSERT INTO orders (order_id, product, quantity) VALUES (NULL, 'Book', 2), ('Pen', 5), ('Notebook', 3);

D. INSERT INTO orders (product, quantity) VALUES ('Book', 2); ('Pen', 5); ('Notebook', 3);

Solution

1. Step 1: Use column list excluding auto-increment column

   Specify only product and quantity columns to let order_id auto-fill.

2. Step 2: Provide multiple value sets separated by commas

   INSERT INTO orders (product, quantity) VALUES ('Book', 2), ('Pen', 5), ('Notebook', 3); correctly uses VALUES with comma-separated tuples.

3. Final Answer:

   INSERT INTO orders (product, quantity) VALUES ('Book', 2), ('Pen', 5), ('Notebook', 3); -> Option A

4. Quick Check:

   Omit auto-increment column, list others, use commas [OK]

Hint: List columns except auto-increment, separate rows with commas [OK]

Common Mistakes:

• Omitting column list when not providing all columns
• Using semicolons between rows
• Inserting NULL explicitly for auto-increment column