Migrate from varchar to text not work

[halfcrazy]

GORM Playground Link

go-gorm/playground#1

Description

[github-actions]

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[tfonfara]

Unfortunately it seems that the fix of this ticket is not perfectly fine, especially this part:

// check type
if !field.PrimaryKey && !strings.HasPrefix(fullDataType, realDataType) {
	alterColumn = true
}

I was wondering why after updating gorm the auto migration was taking so long. I found that I was using type int32 (not null) in my models, which caused the issue. While debugging I found that in here for int32 and postgres dialect the fullDataType is integer not null and realDataType is int4 which is fine in general but due to the upper code snippet it runs a migration every time for all int32 fields.

@a631807682 is there any chance to limit this condition to the mentioned data types, as this might affect others as well.

[a631807682]

related to go-gorm/postgres#111
@tfonfara integer is alias for int4, it will be fix after this PR merge.