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3. Column Definition

Auto-increment columns must not use signed integers​

Code: SignedInteger4IdentityColumnDisallowed

Rule Description: The use of signed integer types in auto-increment columns is prohibited to avoid potential overflow issues.

Warning Level: Warning

Review Object: CREATE TABLE

Trigger Condition: Auto-increment columns use signed integer types.

Configurable: Yes

Example: The expression can be configured as unsigned int/unsigned bigint, indicating that auto-increment columns should use these unsigned integer types.

Supported Database Types: All

Auto-increment columns should start with an initial value of 0/1​

Code: InitValue4IdentityColumn

Rule Description: Auto-increment columns should start with an initial value of 0 or 1 to ensure that the generated key values are unique.

Warning Level: Warning

Review Object: CREATE TABLE

Trigger Condition: The initial value of auto-increment columns is not 0 or 1.

Configurable: Yes

Example: The expression can be configured as 1, indicating that the initial value of auto-increment columns should start from 1.

Supported Database Types: All

Auto-increment sequence exhaustion warning​

Code: CacheExhausted4IdentityColumn

Rule Description: A warning should be issued when the auto-increment sequence approaches its maximum value to avoid sequence exhaustion.

Warning Level: Warning

Review Object: CREATE TABLE

Trigger Condition: The current value of the auto-increment sequence is close to its maximum value preset threshold (e.g., 0.8).

Configurable: Yes

Example: The expression can be configured as 0.8, indicating that a warning should be issued when the auto-increment sequence reaches 80% of its maximum value.

Supported Database Types: All

ENUM data type is prohibited​

Code: EnumDataTypeDisallowed

Rule Description: The use of the ENUM data type is prohibited because it is not a SQL standard type, which may lead to portability issues and difficulties in data maintenance.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE ADD COLUMN

Trigger Condition: Columns are defined using the ENUM data type.

Configurable: No

Supported Database Types: All

SET data type is prohibited​

Code: SetDataTypeDisallowed

Rule Description: The use of the SET data type is prohibited because it may lead to increased complexity in data maintenance and querying.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE ADD COLUMN

Trigger Condition: Columns are defined using the SET data type.

Configurable: No

Supported Database Types: All

Timestamp columns must specify default values​

Code: DefaultValue4TimeStampColumnsRequired

Rule Description: Timestamp columns must specify default values to ensure that a reasonable default time is automatically generated when no explicit timestamp value is inserted.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE ADD COLUMN

Trigger Condition: Timestamp columns do not specify default values.

Configurable: No

Supported Database Types: All

Code: UseInt10Bigint20ForInteger

Rule Description: It is recommended to use INT(10) or BIGINT(20) for integer fields to optimize storage space and performance.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE MODIFY COLUMN

Trigger Condition: Integer fields do not use the recommended INT(10) or BIGINT(20).

Configurable: No

Supported Database Types: All

Code: UseDecimalForNumericColumns

Rule Description: For floating-point numbers that require precise representation, it is recommended to use the DECIMAL type to avoid precision issues in floating-point arithmetic.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE MODIFY COLUMN

Trigger Condition: Floating-point types are used instead of DECIMAL.

Configurable: No

Supported Database Types: All

Non-null fields must have default values​

Code: DefaultValue4NonNullColumnsRequired

Rule Description: Fields defined as non-null (NOT NULL) must specify default values to avoid errors when inserting data.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE MODIFY COLUMN

Trigger Condition: Non-null fields do not specify default values.

Configurable: No

Supported Database Types: All

Tables must define update timestamp columns​

Code: UpdateTimeStampColumnsRequired

Rule Description: It is required that tables include update timestamp columns to record the last update time of the data, which helps track data changes.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE ADD COLUMN

Trigger Condition: Tables do not define update timestamp columns.

Configurable: No

Supported Database Types: All

VARCHAR field length exceeds threshold​

Code: Length4VarcharExceedThreshold

Rule Description: The maximum length of VARCHAR fields is limited to avoid performance issues and unnecessary storage costs.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE MODIFY COLUMN

Trigger Condition: The length of VARCHAR fields exceeds the preset threshold (e.g., 10000).

Configurable: Yes

Example: The expression can be configured as 10000, indicating that the length of VARCHAR fields should not exceed 10000 characters.

Supported Database Types: All

CHAR types exceeding threshold length should be changed to VARCHAR types​

Code: Length4CharColumnExceedThreshold

Rule Description: When the length of CHAR type fields exceeds a certain threshold, it should be considered to change to VARCHAR types to dynamically store data with varying lengths.

Warning Level: Notice

Review Object: CREATE TABLE, ALTER TABLE MODIFY COLUMN

Trigger Condition: The length of CHAR fields exceeds the preset threshold (e.g., 64).

Configurable: Yes

Example: The expression can be configured as 64, indicating that the length of CHAR fields should not exceed 64 characters.

Supported Database Types: All

Timestamp type is prohibited​

Code: TimestampDatatypeDisallowed

Rule Description: The use of the timestamp type is prohibited because it may have a maximum value limit and time zone conversion issues.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE ADD COLUMN

Trigger Condition: Columns are defined using the timestamp type.

Configurable: No

Supported Database Types: MySQL

Prohibited data types​

Code: DataTypesDisallowed

Rule Description: Certain data types are prohibited because they are not supported or not recommended for use.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE ADD COLUMN

Trigger Condition: Prohibited data types are used (e.g., JSON, BJSON, XML).

Configurable: Yes

Example: The expression can be configured as JSON,BJSON,XML, indicating that the use of JSON, BJSON, and XML data types is prohibited.

Supported Database Types: All

Time or date-time type fields must set default values or default values must not be empty​

Code: DefaultValue4TimeOrDateTimeColumnsRequired

Rule Description: Fields of time or date-time types must set default values to avoid generating invalid date-time values during insertion operations.

Warning Level: Warning

Review Object: CREATE TABLE, ALTER TABLE ADD COLUMN

Trigger Condition: Fields of time or date-time types do not set default values or default values are empty.

Configurable: No

Supported Database Types: All