# Isolation Level (Continue...)

+ Dirty read
  + Transaction A modify the data data, but it was not committed;
  + At the same time, transaction B reads the modify of the data, which is called a dirty read.
+ Non-Repeatable Read
  + Between two read of data in transaction A, transaction B accesses data data, modify data, and commits.
  + If transaction A is read twice before and after due to modify of transaction B, the inconsistencies are called Non-Repeatable Read.
+ phantom read
  + The main difference from Non-Repeatable Read is that phantom reads involve inserts, whereas Non-Repeatable Read are mostly updates.
  + Transaction A read a range of data and modifies it, while transaction B adds a new row of insert data to the range.
  + Transaction A is repeatable and can read the original data, but when it is committed, it is found that there is data that has not been found before insert data.
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- Dirty read
  - Transaction A modify the data data, but it was not committed
  - At the same time transaction B reads the modify of the data, which is called a dirty read.

- Non-Repeatable Read
  - Between two read of data in transaction A, transaction B accesses the data data, modify the data, and commits it.
  - If transaction A is read twice before and after due to modify of transaction B, the inconsistency is called Non-Repeatable Read.

- phantom read
  - The main difference from Non-Repeatable Read is that phantom reads involve inserts, whereas Non-Repeatable Read are mostly updates.
  - Transaction A read a range of data in DB and modifies it, while transaction B adds a new row of insert_data to the range.
  - Transaction A can be read repeatedly, and the original data can be read, but it is found that there is data insert_data that has not been found before when it is submitted.