feat(sqlite): add SQLite type mapping and conversion functions

* Implement SQLiteToCanonicalTypes for type mapping
* Add ConvertSQLiteToCanonical and ConvertCanonicalToSQLite functions
* Update mapDataType to utilize new conversion logic

pkg/mariadb/datatypes.go

@@ -0,0 +1,156 @@
+package mariadb
+
+import "strings"
+
+// MariaDBToCanonicalTypes maps MariaDB/MySQL type names to canonical types.
+var MariaDBToCanonicalTypes = map[string]string{
+	// Integer types
+	"tinyint":   "int8",
+	"smallint":  "int16",
+	"mediumint": "int",
+	"int":       "int",
+	"integer":   "int",
+	"int2":      "int16",
+	"int4":      "int",
+	"int8":      "int64",
+	"bigint":    "int64",
+	// Boolean (TINYINT(1) alias)
+	"boolean": "bool",
+	"bool":    "bool",
+	"bit":     "bool",
+	// Float types
+	"float":            "float32",
+	"double":           "float64",
+	"real":             "float64",
+	"double precision": "float64",
+	// Decimal types
+	"decimal": "decimal",
+	"numeric": "decimal",
+	"dec":     "decimal",
+	"fixed":   "decimal",
+	// String types
+	"char":       "string",
+	"character":  "string",
+	"varchar":    "string",
+	"nchar":      "string",
+	"nvarchar":   "string",
+	"tinytext":   "text",
+	"text":       "text",
+	"mediumtext": "text",
+	"longtext":   "text",
+	// Binary/blob types
+	"binary":     "bytea",
+	"varbinary":  "bytea",
+	"tinyblob":   "bytea",
+	"blob":       "bytea",
+	"mediumblob": "bytea",
+	"longblob":   "bytea",
+	// Date/time types
+	"date":      "date",
+	"time":      "time",
+	"datetime":  "timestamp",
+	"timestamp": "timestamp",
+	"year":      "int",
+	// Other types
+	"json": "json",
+	"enum": "string",
+	"set":  "string",
+	"uuid": "uuid",
+}
+
+// CanonicalToMariaDBTypes maps canonical types to MariaDB/MySQL types.
+var CanonicalToMariaDBTypes = map[string]string{
+	"bool":        "TINYINT(1)",
+	"int8":        "TINYINT",
+	"int16":       "SMALLINT",
+	"int":         "INT",
+	"int32":       "INT",
+	"int64":       "BIGINT",
+	"uint":        "INT UNSIGNED",
+	"uint8":       "TINYINT UNSIGNED",
+	"uint16":      "SMALLINT UNSIGNED",
+	"uint32":      "INT UNSIGNED",
+	"uint64":      "BIGINT UNSIGNED",
+	"float32":     "FLOAT",
+	"float64":     "DOUBLE",
+	"decimal":     "DECIMAL",
+	"string":      "VARCHAR(255)",
+	"text":        "TEXT",
+	"date":        "DATE",
+	"time":        "TIME",
+	"timestamp":   "DATETIME",
+	"timestamptz": "DATETIME",
+	"uuid":        "CHAR(36)",
+	"json":        "JSON",
+	"jsonb":       "JSON",
+	"bytea":       "BLOB",
+}
+
+// MariaDBTypeSynonyms maps MariaDB/MySQL type aliases to their canonical MariaDB name.
+var MariaDBTypeSynonyms = map[string]string{
+	"integer":          "int",
+	"int2":             "smallint",
+	"int4":             "int",
+	"int8":             "bigint",
+	"double precision": "double",
+	"character":        "char",
+	"dec":              "decimal",
+	"fixed":            "decimal",
+	"numeric":          "decimal",
+	"boolean":          "tinyint",
+	"bool":             "tinyint",
+}
+
+// NormalizeMariaDBType maps a MariaDB/MySQL base type (no dimension parameters)
+// to its canonical MariaDB form. Unknown types are returned as-is (lowercased).
+func NormalizeMariaDBType(baseType string) string {
+	lower := strings.ToLower(strings.TrimSpace(baseType))
+	if canonical, ok := MariaDBTypeSynonyms[lower]; ok {
+		return canonical
+	}
+	return lower
+}
+
+// ConvertMariaDBToCanonical converts a MariaDB/MySQL type name to the canonical type.
+// Strips dimension parameters and normalizes aliases. Defaults to "string".
+func ConvertMariaDBToCanonical(mariadbType string) string {
+	base := strings.ToLower(strings.TrimSpace(mariadbType))
+	if idx := strings.Index(base, "("); idx >= 0 {
+		base = strings.TrimSpace(base[:idx])
+	}
+
+	if canonical, ok := MariaDBToCanonicalTypes[base]; ok {
+		return canonical
+	}
+
+	// Prefix match for composite types (e.g., "unsigned bigint")
+	for key, canonical := range MariaDBToCanonicalTypes {
+		if strings.HasPrefix(base, key) {
+			return canonical
+		}
+	}
+
+	return "string"
+}
+
+// ConvertCanonicalToMariaDB converts a canonical type to a MariaDB/MySQL type.
+// Defaults to VARCHAR(255) for unrecognised types.
+func ConvertCanonicalToMariaDB(canonicalType string) string {
+	lower := strings.ToLower(strings.TrimSpace(canonicalType))
+	if idx := strings.Index(lower, "("); idx >= 0 {
+		lower = strings.TrimSpace(lower[:idx])
+	}
+
+	if mariadbType, ok := CanonicalToMariaDBTypes[lower]; ok {
+		return mariadbType
+	}
+
+	// Prefix fallback
+	for canonical, mariadb := range CanonicalToMariaDBTypes {
+		if strings.HasPrefix(lower, canonical) {
+			return mariadb
+		}
+	}
+
+	return "VARCHAR(255)"
+}

pkg/mssql/datatypes.go

@@ -2,32 +2,73 @@ package mssql
 
 import "strings"
 
-// CanonicalToMSSQLTypes maps canonical types to MSSQL types
+// CanonicalToMSSQLTypes maps canonical types to MSSQL types.
+// Accepts both Go canonical names ("int", "string") and SQL canonical names
+// ("integer", "varchar") so the writer handles input from any reader.
 var CanonicalToMSSQLTypes = map[string]string{
+	// Boolean — Go and SQL canonical
 	"bool":    "BIT",
+	"boolean": "BIT",
+	// Integer — Go canonical
 	"int8":   "TINYINT",
 	"int16":  "SMALLINT",
 	"int":    "INT",
 	"int32":  "INT",
 	"int64":  "BIGINT",
 	"uint":   "BIGINT",
-	"uint8":       "SMALLINT",
+	"uint8":  "TINYINT",
-	"uint16":      "INT",
+	"uint16": "SMALLINT",
 	"uint32": "BIGINT",
 	"uint64": "BIGINT",
+	// Integer — SQL canonical (serial types map to base integer; IDENTITY is set via AutoIncrement)
+	"integer":      "INT",
+	"smallint":     "SMALLINT",
+	"bigint":       "BIGINT",
+	"tinyint":      "TINYINT",
+	"serial":       "INT",
+	"smallserial":  "SMALLINT",
+	"bigserial":    "BIGINT",
+	// Float — Go canonical
 	"float32": "REAL",
 	"float64": "FLOAT",
+	// Float — SQL canonical
+	"real":             "REAL",
+	"double precision": "FLOAT",
+	"double":           "FLOAT",
+	// Decimal/numeric
 	"decimal": "NUMERIC",
+	"numeric": "NUMERIC",
+	"money":   "MONEY",
+	// String — Go canonical
 	"string": "NVARCHAR(255)",
 	"text":   "NVARCHAR(MAX)",
+	// String — SQL canonical
+	"varchar":  "NVARCHAR(255)",
+	"char":     "NCHAR",
+	"nvarchar": "NVARCHAR(255)",
+	"nchar":    "NCHAR",
+	"citext":   "NVARCHAR(MAX)",
+	// Date/time
 	"date":        "DATE",
 	"time":        "TIME",
+	"timetz":      "DATETIMEOFFSET",
 	"timestamp":   "DATETIME2",
 	"timestamptz": "DATETIMEOFFSET",
+	"datetime":    "DATETIME2",
+	"interval":    "NVARCHAR(50)",
+	// UUID
 	"uuid": "UNIQUEIDENTIFIER",
+	// JSON — MSSQL has no native JSON type; stored as NVARCHAR(MAX)
 	"json":  "NVARCHAR(MAX)",
 	"jsonb": "NVARCHAR(MAX)",
+	// Binary
 	"bytea": "VARBINARY(MAX)",
+	"blob":  "VARBINARY(MAX)",
+	// Network/geo types — no MSSQL native equivalent
+	"xml":     "XML",
+	"inet":    "NVARCHAR(45)",
+	"cidr":    "NVARCHAR(43)",
+	"macaddr": "NVARCHAR(17)",
 }
 
 // MSSQLToCanonicalTypes maps MSSQL types to canonical types
@@ -68,47 +109,50 @@ var MSSQLToCanonicalTypes = map[string]string{
 	"geometry":         "string",
 }
 
-// ConvertCanonicalToMSSQL converts a canonical type to MSSQL type
+// MSSQLTypeSynonyms maps MSSQL type aliases to their canonical MSSQL name.
+var MSSQLTypeSynonyms = map[string]string{
+	"integer":  "int",
+	"dec":      "decimal",
+	"float(n)": "float",
+}
+
+// NormalizeMSSQLType maps an MSSQL base type (no dimension parameters) to its
+// canonical MSSQL form. Unknown types are returned as-is (lowercased).
+func NormalizeMSSQLType(baseType string) string {
+	lower := strings.ToLower(strings.TrimSpace(baseType))
+	if canonical, ok := MSSQLTypeSynonyms[lower]; ok {
+		return canonical
+	}
+	return lower
+}
+
+// ConvertCanonicalToMSSQL converts a canonical type (Go or SQL) to an MSSQL type.
+// Strips dimension parameters before lookup. Defaults to NVARCHAR(255) for unknown types.
 func ConvertCanonicalToMSSQL(canonicalType string) string {
-	// Check direct mapping
+	base := strings.ToLower(strings.TrimSpace(canonicalType))
-	if mssqlType, exists := CanonicalToMSSQLTypes[strings.ToLower(canonicalType)]; exists {
+	if idx := strings.Index(base, "("); idx >= 0 {
+		base = strings.TrimSpace(base[:idx])
+	}
+	base = strings.TrimSuffix(base, "[]")
+
+	if mssqlType, exists := CanonicalToMSSQLTypes[base]; exists {
 		return mssqlType
 	}
 
-	// Try to find by prefix
-	lowerType := strings.ToLower(canonicalType)
-	for canonical, mssql := range CanonicalToMSSQLTypes {
-		if strings.HasPrefix(lowerType, canonical) {
-			return mssql
-		}
-	}
-
-	// Default to NVARCHAR
 	return "NVARCHAR(255)"
 }
 
-// ConvertMSSQLToCanonical converts an MSSQL type to canonical type
+// ConvertMSSQLToCanonical converts an MSSQL type to the canonical type.
+// Strips dimension parameters before lookup. Defaults to "string" for unknown types.
 func ConvertMSSQLToCanonical(mssqlType string) string {
-	// Extract base type (remove parentheses and parameters)
+	base := strings.ToLower(strings.TrimSpace(mssqlType))
-	baseType := mssqlType
+	if idx := strings.Index(base, "("); idx >= 0 {
-	if idx := strings.Index(baseType, "("); idx != -1 {
+		base = strings.TrimSpace(base[:idx])
-		baseType = baseType[:idx]
 	}
-	baseType = strings.TrimSpace(baseType)
 
-	// Check direct mapping
+	if canonicalType, exists := MSSQLToCanonicalTypes[base]; exists {
-	if canonicalType, exists := MSSQLToCanonicalTypes[strings.ToLower(baseType)]; exists {
 		return canonicalType
 	}
 
-	// Try to find by prefix
-	lowerType := strings.ToLower(baseType)
-	for mssql, canonical := range MSSQLToCanonicalTypes {
-		if strings.HasPrefix(lowerType, mssql) {
-			return canonical
-		}
-	}
-
-	// Default to string
 	return "string"
 }

pkg/readers/pgsql/queries.go

@@ -270,8 +270,16 @@ func (r *Reader) queryColumns(schemaName string) (map[string]map[string]*models.
 		}
 
 		if numPrecision != nil {
+			// For integer and serial types, numeric_precision is a bit-width (32, 64, 16)
+			// not a user-visible column parameter. Only store precision for types where
+			// it represents actual decimal/scale precision (numeric, decimal, float).
+			switch column.Type {
+			case "integer", "bigint", "smallint", "serial", "bigserial", "smallserial":
+				// skip — bit-width, not a column parameter
+			default:
 				column.Precision = *numPrecision
 			}
+		}
 
 		if numScale != nil {
 			column.Scale = *numScale

pkg/readers/sqlite/reader.go

@@ -10,6 +10,7 @@ import (
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/readers"
+	sqlitepkg "git.warky.dev/wdevs/relspecgo/pkg/sqlite"
 )
 
 // Reader implements the readers.Reader interface for SQLite databases
@@ -183,59 +184,9 @@ func (r *Reader) close() {
 	}
 }
 
-// mapDataType maps SQLite data types to canonical types
+// mapDataType maps SQLite data types to canonical types.
 func (r *Reader) mapDataType(sqliteType string) string {
-	// SQLite has a flexible type system, but we map common types
+	return sqlitepkg.ConvertSQLiteToCanonical(sqliteType)
-	typeMap := map[string]string{
-		"INTEGER":           "int",
-		"INT":               "int",
-		"TINYINT":           "int8",
-		"SMALLINT":          "int16",
-		"MEDIUMINT":         "int",
-		"BIGINT":            "int64",
-		"UNSIGNED BIG INT":  "uint64",
-		"INT2":              "int16",
-		"INT8":              "int64",
-		"REAL":              "float64",
-		"DOUBLE":            "float64",
-		"DOUBLE PRECISION":  "float64",
-		"FLOAT":             "float32",
-		"NUMERIC":           "decimal",
-		"DECIMAL":           "decimal",
-		"BOOLEAN":           "bool",
-		"BOOL":              "bool",
-		"DATE":              "date",
-		"DATETIME":          "timestamp",
-		"TIMESTAMP":         "timestamp",
-		"TEXT":              "string",
-		"VARCHAR":           "string",
-		"CHAR":              "string",
-		"CHARACTER":         "string",
-		"VARYING CHARACTER": "string",
-		"NCHAR":             "string",
-		"NVARCHAR":          "string",
-		"CLOB":              "text",
-		"BLOB":              "bytea",
-	}
-
-	// Try exact match first
-	if mapped, exists := typeMap[sqliteType]; exists {
-		return mapped
-	}
-
-	// Try case-insensitive match for common types
-	sqliteTypeUpper := sqliteType
-	if len(sqliteType) > 0 {
-		// Extract base type (e.g., "VARCHAR(255)" -> "VARCHAR")
-		for baseType := range typeMap {
-			if len(sqliteTypeUpper) >= len(baseType) && sqliteTypeUpper[:len(baseType)] == baseType {
-				return typeMap[baseType]
-			}
-		}
-	}
-
-	// Default to string for unknown types
-	return "string"
 }
 
 // deriveRelationship creates a relationship from a foreign key constraint

pkg/sqlite/datatypes.go

@@ -0,0 +1,152 @@
+package sqlite
+
+import "strings"
+
+// SQLiteToCanonicalTypes maps SQLite type names to canonical types.
+// SQLite has type affinity rules; this maps common type names including
+// MySQL/PostgreSQL types that users write in SQLite schemas.
+var SQLiteToCanonicalTypes = map[string]string{
+	// Integer affinity
+	"integer":          "int",
+	"int":              "int",
+	"tinyint":          "int8",
+	"smallint":         "int16",
+	"mediumint":        "int",
+	"bigint":           "int64",
+	"unsigned big int": "uint64",
+	"int2":             "int16",
+	"int8":             "int64",
+	// Real affinity
+	"real":             "float64",
+	"double":           "float64",
+	"double precision": "float64",
+	"float":            "float32",
+	// Numeric affinity
+	"numeric": "decimal",
+	"decimal": "decimal",
+	// Boolean (stored as integer in SQLite)
+	"boolean": "bool",
+	"bool":    "bool",
+	// Date/time (stored as text in SQLite)
+	"date":      "date",
+	"datetime":  "timestamp",
+	"timestamp": "timestamp",
+	// Text affinity
+	"text":              "string",
+	"varchar":           "string",
+	"char":              "string",
+	"character":         "string",
+	"varying character": "string",
+	"nchar":             "string",
+	"nvarchar":          "string",
+	"clob":              "text",
+	// Blob affinity
+	"blob": "bytea",
+}
+
+// CanonicalToSQLiteAffinity maps type names to SQLite type affinity names.
+// Accepts both Go canonical names ("int", "string") and SQL canonical names
+// ("integer", "varchar") so the writer handles input from any reader.
+// The five SQLite type affinities are TEXT, INTEGER, REAL, NUMERIC, BLOB.
+var CanonicalToSQLiteAffinity = map[string]string{
+	// INTEGER affinity — Go canonical
+	"int":    "INTEGER",
+	"int8":   "INTEGER",
+	"int16":  "INTEGER",
+	"int32":  "INTEGER",
+	"int64":  "INTEGER",
+	"uint":   "INTEGER",
+	"uint8":  "INTEGER",
+	"uint16": "INTEGER",
+	"uint32": "INTEGER",
+	"uint64": "INTEGER",
+	"bool":   "INTEGER",
+	// INTEGER affinity — SQL canonical
+	"integer":     "INTEGER",
+	"smallint":    "INTEGER",
+	"bigint":      "INTEGER",
+	"serial":      "INTEGER",
+	"smallserial": "INTEGER",
+	"bigserial":   "INTEGER",
+	"boolean":     "INTEGER",
+	"tinyint":     "INTEGER",
+	"mediumint":   "INTEGER",
+	// REAL affinity — Go canonical
+	"float32": "REAL",
+	"float64": "REAL",
+	// REAL affinity — SQL canonical
+	"real":             "REAL",
+	"float":            "REAL",
+	"double":           "REAL",
+	"double precision": "REAL",
+	// NUMERIC affinity
+	"decimal":    "NUMERIC",
+	"numeric":    "NUMERIC",
+	"money":      "NUMERIC",
+	"smallmoney": "NUMERIC",
+	// BLOB affinity
+	"bytea": "BLOB",
+	"blob":  "BLOB",
+	// TEXT affinity — Go canonical
+	"string": "TEXT",
+	"text":   "TEXT",
+	// TEXT affinity — SQL canonical
+	"varchar":     "TEXT",
+	"char":        "TEXT",
+	"nvarchar":    "TEXT",
+	"nchar":       "TEXT",
+	"citext":      "TEXT",
+	"date":        "TEXT",
+	"time":        "TEXT",
+	"timetz":      "TEXT",
+	"timestamp":   "TEXT",
+	"timestamptz": "TEXT",
+	"datetime":    "TEXT",
+	"uuid":        "TEXT",
+	"json":        "TEXT",
+	"jsonb":       "TEXT",
+	"xml":         "TEXT",
+	"inet":        "TEXT",
+	"cidr":        "TEXT",
+	"macaddr":     "TEXT",
+}
+
+// ConvertSQLiteToCanonical converts a SQLite type name to the canonical type.
+// Strips dimension parameters (e.g. VARCHAR(255) → string) and handles
+// SQLite's flexible affinity rules. Defaults to "string" for unknown types.
+func ConvertSQLiteToCanonical(sqliteType string) string {
+	base := strings.ToUpper(strings.TrimSpace(sqliteType))
+	if idx := strings.Index(base, "("); idx >= 0 {
+		base = strings.TrimSpace(base[:idx])
+	}
+	lower := strings.ToLower(base)
+
+	if canonical, ok := SQLiteToCanonicalTypes[lower]; ok {
+		return canonical
+	}
+
+	// Prefix match for types like "VARYING CHARACTER(255)"
+	for key, canonical := range SQLiteToCanonicalTypes {
+		if strings.HasPrefix(lower, key) {
+			return canonical
+		}
+	}
+
+	return "string"
+}
+
+// ConvertCanonicalToSQLite converts a canonical type (or any SQL type) to its
+// SQLite type affinity. Defaults to TEXT for unrecognised types.
+func ConvertCanonicalToSQLite(canonicalType string) string {
+	normalized := strings.ToLower(strings.TrimSpace(canonicalType))
+	if idx := strings.Index(normalized, "("); idx >= 0 {
+		normalized = strings.TrimSpace(normalized[:idx])
+	}
+	normalized = strings.TrimSuffix(normalized, "[]")
+
+	if affinity, ok := CanonicalToSQLiteAffinity[normalized]; ok {
+		return affinity
+	}
+
+	return "TEXT"
+}

pkg/writers/sqlite/datatypes.go

@@ -3,10 +3,10 @@ package sqlite
 import (
 	"strings"
 
-	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
+	sqlitepkg "git.warky.dev/wdevs/relspecgo/pkg/sqlite"
 )
 
-// SQLite type affinities
+// SQLite type affinity constants
 const (
 	TypeText    = "TEXT"
 	TypeInteger = "INTEGER"
@@ -15,55 +15,27 @@ const (
 	TypeBlob    = "BLOB"
 )
 
-// MapPostgreSQLType maps PostgreSQL data types to SQLite type affinities
+// MapTypeToSQLite maps any SQL or Go canonical type to a SQLite type affinity.
+// Handles input from any reader (PostgreSQL, MSSQL, SQLite, Go canonical).
+func MapTypeToSQLite(colType string) string {
+	return sqlitepkg.ConvertCanonicalToSQLite(colType)
+}
+
+// MapPostgreSQLType is an alias for MapTypeToSQLite kept for compatibility.
+//
+// Deprecated: use MapTypeToSQLite.
 func MapPostgreSQLType(pgType string) string {
-	normalized := strings.ToLower(strings.TrimSpace(pgType))
+	return MapTypeToSQLite(pgType)
-	normalized = strings.TrimSuffix(normalized, "[]")
-	if idx := strings.Index(normalized, "("); idx != -1 {
-		normalized = normalized[:idx]
-	}
-	// Resolve synonyms to canonical form before mapping
-	normalized = pgsql.NormalizePGType(normalized)
-
-	switch normalized {
-	case "varchar", "char", "text", "citext", "uuid",
-		"timestamp", "timestamptz", "date", "time", "timetz",
-		"json", "jsonb", "xml", "inet", "cidr", "macaddr":
-		return TypeText
-	case "integer", "smallint", "bigint",
-		"serial", "smallserial", "bigserial", "boolean":
-		return TypeInteger
-	case "real", "float", "double precision":
-		return TypeReal
-	case "numeric", "money":
-		return TypeNumeric
-	case "bytea", "blob":
-		return TypeBlob
-	default:
-		return TypeText
-	}
 }
 
-// IsIntegerType checks if a column type should be treated as integer
+// IsIntegerType reports whether a column type maps to SQLite INTEGER affinity.
 func IsIntegerType(colType string) bool {
-	normalized := strings.ToLower(strings.TrimSpace(colType))
+	return MapTypeToSQLite(colType) == TypeInteger
-	normalized = strings.TrimSuffix(normalized, "[]")
-	if idx := strings.Index(normalized, "("); idx != -1 {
-		normalized = normalized[:idx]
-	}
-	normalized = pgsql.NormalizePGType(normalized)
-	switch normalized {
-	case "integer", "smallint", "bigint", "serial", "smallserial", "bigserial":
-		return true
-	default:
-		return false
-	}
 }
 
-// MapBooleanValue converts PostgreSQL boolean literals to SQLite (0/1)
+// MapBooleanValue converts common boolean literals to SQLite integers (1/0).
 func MapBooleanValue(value string) string {
-	normalized := strings.ToLower(strings.TrimSpace(value))
+	switch strings.ToLower(strings.TrimSpace(value)) {
-	switch normalized {
 	case "true", "t", "yes", "y", "1":
 		return "1"
 	case "false", "f", "no", "n", "0":