String types (VARCHAR, CHAR, TEXT) in MySQL - Step-by-Step Execution

Concept Flow - String types (VARCHAR, CHAR, TEXT)

Start: Define column with string type

↓

Choose type: CHAR, VARCHAR, or TEXT?

↓

CHAR

↓

Fixed length

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Store data

↓

End

When creating a string column, you pick CHAR for fixed length, VARCHAR for variable length, or TEXT for large text storage.

Execution Sample

MySQL

CREATE TABLE example (
  col_char CHAR(5),
  col_varchar VARCHAR(5),
  col_text TEXT
);

This creates a table with three string columns: fixed length CHAR, variable length VARCHAR, and large TEXT.

Execution Table

Step	Action	Column	Type	Storage Behavior	Result
1	Define column	col_char	CHAR(5)	Fixed length, pads with spaces if shorter	Column created
2	Define column	col_varchar	VARCHAR(5)	Variable length, stores only actual chars	Column created
3	Define column	col_text	TEXT	Stores large text, up to 65,535 bytes	Column created
4	Insert 'abc' into col_char	col_char	CHAR(5)	Stores 'abc ' (padded with 2 spaces)	Value stored as 'abc '
5	Insert 'abc' into col_varchar	col_varchar	VARCHAR(5)	Stores 'abc' exactly	Value stored as 'abc'
6	Insert 'abc' into col_text	col_text	TEXT	Stores 'abc' exactly	Value stored as 'abc'
7	Retrieve col_char	col_char	CHAR(5)	Returns 'abc' (trailing spaces removed)	Output: 'abc'
8	Retrieve col_varchar	col_varchar	VARCHAR(5)	Returns 'abc' exactly	Output: 'abc'
9	Retrieve col_text	col_text	TEXT	Returns 'abc' exactly	Output: 'abc'
10	Insert 'abcdef' into col_char	col_char	CHAR(5)	Truncates to 5 chars 'abcde'	Value stored as 'abcde'
11	Insert 'abcdef' into col_varchar	col_varchar	VARCHAR(5)	Error: Data too long, insert fails	Insert fails
12	Insert large text into col_text	col_text	TEXT	Stores large text up to limit	Value stored
13	Insert text > 65,535 bytes into col_text	col_text	TEXT	Error: data too long	Insert fails
14	End				Table ready with string columns

💡 Execution stops after table creation and data insertion steps complete or error occurs.

Variable Tracker

Variable	Start	After Step 4	After Step 5	After Step 6	After Step 10	After Step 11	After Step 12	After Step 13	Final
col_char	NULL	'abc '	'abc '	'abc '	'abcde'	'abcde'	'abcde'	'abcde'	'abcde'
col_varchar	NULL	NULL	'abc'	'abc'	'abc'	NULL	NULL	NULL	NULL
col_text	NULL	NULL	NULL	'abc'	'abc'	'abc'	'large text'	'large text'	'large text'

Key Moments - 3 Insights

Why does CHAR(5) store 'abc' as 'abc ' with spaces?

CHAR is fixed length, so shorter strings are padded with spaces to fill the defined length, as shown in execution_table step 4.

Why does VARCHAR(5) store 'abc' without extra spaces?

VARCHAR stores only the actual characters without padding, so 'abc' is stored exactly as is, as seen in step 5.

What happens if you insert more characters than the defined length in CHAR or VARCHAR?

For CHAR, the string is truncated to the maximum length allowed, as shown in step 10 where 'abcdef' becomes 'abcde'. For VARCHAR, inserting more characters than the defined length causes an error and the insert fails, as shown in step 11.

Visual Quiz - 3 Questions

Look at the execution_table at step 4. What is stored in col_char after inserting 'abc'?

A 'abcde' (truncated)

B 'abc' (no padding)

C 'abc ' (padded with spaces)

D NULL

💡 Hint

Check the Storage Behavior column in step 4 of execution_table.

At which step does inserting too large text into col_text cause an error?

A Step 12

B Step 13

C Step 10

D Step 5

💡 Hint

Look for the row mentioning 'Error: data too long' in execution_table.

If you insert 'abcdef' into col_varchar(5), what will be stored according to the execution_table?

A NULL

B 'abcde' (truncated to 5 chars)

C 'abc ' (padded with spaces)

D 'abcdef' (full string)

💡 Hint

See step 11 in execution_table for VARCHAR behavior on longer input.

Concept Snapshot

String types in MySQL:
- CHAR(n): fixed length, pads with spaces
- VARCHAR(n): variable length, stores exact chars
- TEXT: large text storage, up to 65,535 bytes
Inserts longer than defined length truncate for CHAR
Inserts longer than defined length for VARCHAR cause error and fail
TEXT cannot exceed its max size or insert fails

Full Transcript

This visual execution shows how MySQL string types CHAR, VARCHAR, and TEXT behave when defining columns and inserting data. CHAR stores fixed length strings padded with spaces. VARCHAR stores variable length strings exactly. TEXT stores large text up to a limit. When inserting shorter strings into CHAR, spaces are added to fill length. VARCHAR stores only actual characters. Inserting longer strings than allowed truncates them for CHAR. For VARCHAR, inserting longer strings than allowed causes an error and the insert fails. TEXT can store large text but errors if too large. The execution table traces each step of defining columns, inserting values, and retrieving them, showing how data is stored and returned. The variable tracker shows how column values change after each insert. Key moments clarify common confusions about padding, truncation, and errors. The quiz tests understanding of these behaviors referencing the execution steps.