1. 实现配置文件解析

2. 实现数据库连接

vendor/gorm.io/gorm/errors.go

@@ -0,0 +1,52 @@
+package gorm
+
+import (
+	"errors"
+
+	"gorm.io/gorm/logger"
+)
+
+var (
+	// ErrRecordNotFound record not found error
+	ErrRecordNotFound = logger.ErrRecordNotFound
+	// ErrInvalidTransaction invalid transaction when you are trying to `Commit` or `Rollback`
+	ErrInvalidTransaction = errors.New("invalid transaction")
+	// ErrNotImplemented not implemented
+	ErrNotImplemented = errors.New("not implemented")
+	// ErrMissingWhereClause missing where clause
+	ErrMissingWhereClause = errors.New("WHERE conditions required")
+	// ErrUnsupportedRelation unsupported relations
+	ErrUnsupportedRelation = errors.New("unsupported relations")
+	// ErrPrimaryKeyRequired primary keys required
+	ErrPrimaryKeyRequired = errors.New("primary key required")
+	// ErrModelValueRequired model value required
+	ErrModelValueRequired = errors.New("model value required")
+	// ErrModelAccessibleFieldsRequired model accessible fields required
+	ErrModelAccessibleFieldsRequired = errors.New("model accessible fields required")
+	// ErrSubQueryRequired sub query required
+	ErrSubQueryRequired = errors.New("sub query required")
+	// ErrInvalidData unsupported data
+	ErrInvalidData = errors.New("unsupported data")
+	// ErrUnsupportedDriver unsupported driver
+	ErrUnsupportedDriver = errors.New("unsupported driver")
+	// ErrRegistered registered
+	ErrRegistered = errors.New("registered")
+	// ErrInvalidField invalid field
+	ErrInvalidField = errors.New("invalid field")
+	// ErrEmptySlice empty slice found
+	ErrEmptySlice = errors.New("empty slice found")
+	// ErrDryRunModeUnsupported dry run mode unsupported
+	ErrDryRunModeUnsupported = errors.New("dry run mode unsupported")
+	// ErrInvalidDB invalid db
+	ErrInvalidDB = errors.New("invalid db")
+	// ErrInvalidValue invalid value
+	ErrInvalidValue = errors.New("invalid value, should be pointer to struct or slice")
+	// ErrInvalidValueOfLength invalid values do not match length
+	ErrInvalidValueOfLength = errors.New("invalid association values, length doesn't match")
+	// ErrPreloadNotAllowed preload is not allowed when count is used
+	ErrPreloadNotAllowed = errors.New("preload is not allowed when count is used")
+	// ErrDuplicatedKey occurs when there is a unique key constraint violation
+	ErrDuplicatedKey = errors.New("duplicated key not allowed")
+	// ErrForeignKeyViolated occurs when there is a foreign key constraint violation
+	ErrForeignKeyViolated = errors.New("violates foreign key constraint")
+)