added dump flow

sources/mysql/infoschema.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"regexp"
 	"sort"
 	"strings"
 
@@ -34,6 +35,8 @@ import (
 	"github.com/GoogleCloudPlatform/spanner-migration-tool/streaming"
 )
 
+var collationRegex = regexp.MustCompile(constants.DB_COLLATION_REGEX)
+
 // InfoSchemaImpl is MySQL specific implementation for InfoSchema.
 type InfoSchemaImpl struct {
 	DbName             string

sources/mysql/mysqldump.go

@@ -29,6 +29,7 @@ import (
 	"github.com/GoogleCloudPlatform/spanner-migration-tool/sources/common"
 	"github.com/pingcap/tidb/parser"
 	"github.com/pingcap/tidb/parser/ast"
+	"github.com/pingcap/tidb/parser/format"
 	"github.com/pingcap/tidb/parser/opcode"
 	"github.com/pingcap/tidb/types"
 	driver "github.com/pingcap/tidb/types/parser_driver"
@@ -37,7 +38,7 @@ import (
 var valuesRegexp = regexp.MustCompile("\\((.*?)\\)")
 var insertRegexp = regexp.MustCompile("INSERT\\sINTO\\s(.*?)\\sVALUES\\s")
 var unsupportedRegexp = regexp.MustCompile("function|procedure|trigger")
-var collationRegex = regexp.MustCompile(constants.DB_COLLATION_REGEX)
+var dbcollationRegex = regexp.MustCompile("_[_A-Za-z0-9]+('([^']*)')")
 
 // MysqlSpatialDataTypes is an array of all MySQL spatial data types.
 var MysqlSpatialDataTypes = []string{"geometrycollection", "multipoint", "multilinestring", "multipolygon", "point", "linestring", "polygon", "geometry"}
@@ -254,6 +255,9 @@ func processCreateTable(conv *internal.Conv, stmt *ast.CreateTableStmt) {
 	var keys []schema.Key
 	var fkeys []schema.ForeignKey
 	var index []schema.Index
+
+	checkConstraints := getCheckConstraints(stmt.Constraints)
+
 	for _, element := range stmt.Cols {
 		_, col, constraint, err := processColumn(conv, tableName, element)
 		if err != nil {
@@ -299,7 +303,9 @@ func processCreateTable(conv *internal.Conv, stmt *ast.CreateTableStmt) {
 		ColDefs:      colDef,
 		PrimaryKeys:  keys,
 		ForeignKeys:  fkeys,
-		Indexes:      index}
+		Indexes:      index,
+		CheckConstraints: checkConstraints,
+	}
 	for _, constraint := range stmt.Constraints {
 		processConstraint(conv, tableId, constraint, "CREATE TABLE", conv.SrcSchema[tableId].ColNameIdMap)
 	}
@@ -333,6 +339,35 @@ func processConstraint(conv *internal.Conv, tableId string, constraint *ast.Cons
 	conv.SrcSchema[tableId] = st
 }
 
+// method to get check constraints using tiDB parser
+func getCheckConstraints(constraints []*ast.Constraint) (checkConstraints []schema.CheckConstraint) {
+	for _, constraint := range constraints {
+		if constraint.Tp == ast.ConstraintCheck {
+			exp := expressionToString(constraint.Expr)
+			exp = dbcollationRegex.ReplaceAllString(exp, "$1")
+			checkConstraint := schema.CheckConstraint{
+				Name: constraint.Name,
+				Expr: exp,
+				ExprId: internal.GenerateCheckConstrainstExprId (),
+				Id:   internal.GenerateCheckConstrainstId(),
+			}
+			checkConstraints = append(checkConstraints, checkConstraint)
+		}
+	}
+	return checkConstraints
+}
+
+// converts an AST expression node to its string representation.
+func expressionToString(expr ast.Node) string {
+	var sb strings.Builder
+	restoreCtx := format.NewRestoreCtx(format.DefaultRestoreFlags, &sb)
+	if err := expr.Restore(restoreCtx); err != nil {
+		fmt.Errorf("Error restoring expression: %v\n", err)
+		return ""
+	}
+	return sb.String()
+}
+
 // toSchemaKeys converts a string list of MySQL keys to schema keys.
 // Note that we map all MySQL keys to ascending ordered schema keys.
 // For primary keys: this is fine because MySQL primary keys are always ascending.