Database Design
Normalization
1st normal form:
Getting data into 1st normal for is fairly easy. Data need to be in a table structure and meet the following criteria:
- Each column must contain an “atomic” value. That means that there will be only one value per cell. No arrays or any other manner of representing more than one value will exist in any cell.
- Each column must have a unique name.
- Table must have asset of values that uniquely identifies the row (also known as the primary key of table)
- No two rows are identical
- No repeating groups of data are allowed.
2nd normal form:
Removing rows tat are only partially dependent on the primary key.
3rd normal form:
Finish the normalization process, 3rd normal form s concerned with transitive dependencies. A transitive dependency is a situation where a column exits that is not directly reliant on the primary key. Instead, the field is reliant on some other field, which in turn is dependent on the primary key.
Quick way: look at all the fields in a table and ask if those fields describe the primary key. If not, you’re not there.
1st normal form:
Getting data into 1st normal for is fairly easy. Data need to be in a table structure and meet the following criteria:
- Each column must contain an “atomic” value. That means that there will be only one value per cell. No arrays or any other manner of representing more than one value will exist in any cell.
- Each column must have a unique name.
- Table must have asset of values that uniquely identifies the row (also known as the primary key of table)
- No two rows are identical
- No repeating groups of data are allowed.
2nd normal form:
Removing rows tat are only partially dependent on the primary key.
3rd normal form:
Finish the normalization process, 3rd normal form s concerned with transitive dependencies. A transitive dependency is a situation where a column exits that is not directly reliant on the primary key. Instead, the field is reliant on some other field, which in turn is dependent on the primary key.
Quick way: look at all the fields in a table and ask if those fields describe the primary key. If not, you’re not there.
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