From 2b8a5c88979b270bbe1fcdc17071a2c6007e40ad Mon Sep 17 00:00:00 2001
From: t8y2 <1156263951@qq.com>
Date: Fri, 14 Aug 2026 13:53:03 +0000
Subject: [PATCH] fix(import): use SQL Server float for decimal inference

Refs: #4072
---
 .../lib/__tests__/table/tableImport.spec.ts   | 15 +++++++
 apps/desktop/src/lib/table/tableImport.ts     |  1 +
 crates/dbx-core/src/table_import.rs           | 44 +++++++++++++++++++
 3 files changed, 60 insertions(+)

diff --git a/apps/desktop/src/lib/__tests__/table/tableImport.spec.ts b/apps/desktop/src/lib/__tests__/table/tableImport.spec.ts
index d2c28f76d1..0ed0ee0052 100644
--- a/apps/desktop/src/lib/__tests__/table/tableImport.spec.ts
+++ b/apps/desktop/src/lib/__tests__/table/tableImport.spec.ts
@@ -4,6 +4,7 @@ import {
   buildTableImportParseOptions,
   defaultTableImportEmptyStringAsNull,
   formatTableImportElapsed,
+  importDataTypeForDatabase,
   nextTableImportWizardStep,
   previousTableImportWizardStep,
   requiredImportTargetColumns,
@@ -131,4 +132,18 @@ describe("tableImport", () => {
       created_at: "DATETIME",
     });
   });
+
+  it("uses SQL Server FLOAT for inferred decimal columns", () => {
+    expect(suggestImportTargetDataTypes(["id", "active", "amount", "created_at", "notes"], [[1001, true, "12.5", "2026-07-07 08:15:00", "invoice"]], "sqlserver")).toEqual({
+      id: "BIGINT",
+      active: "BIT",
+      amount: "FLOAT",
+      created_at: "DATETIME2",
+      notes: "NVARCHAR(MAX)",
+    });
+    expect(importDataTypeForDatabase("decimal", "mysql")).toBe("DOUBLE");
+    expect(importDataTypeForDatabase("decimal", "postgres")).toBe("DOUBLE PRECISION");
+    expect(importDataTypeForDatabase("decimal", "sqlite")).toBe("REAL");
+    expect(importDataTypeForDatabase("decimal", "oracle")).toBe("BINARY_DOUBLE");
+  });
 });
diff --git a/apps/desktop/src/lib/table/tableImport.ts b/apps/desktop/src/lib/table/tableImport.ts
index f8a0d56e3c..42870cb709 100644
--- a/apps/desktop/src/lib/table/tableImport.ts
+++ b/apps/desktop/src/lib/table/tableImport.ts
@@ -243,6 +243,7 @@ export function importDataTypeForDatabase(inferredType: ImportInferredType, data
       return "BIGINT";
     case "decimal":
       if (["postgres", "gaussdb", "opengauss", "redshift", "kingbase", "highgo", "uxdb", "kwdb", "vastbase"].includes(databaseType || "")) return "DOUBLE PRECISION";
+      if (databaseType === "sqlserver") return "FLOAT";
       if (databaseType === "sqlite" || databaseType === "rqlite" || databaseType === "turso" || databaseType === "cloudflare-d1") return "REAL";
       if (databaseType === "oracle" || databaseType === "oceanbase-oracle" || databaseType === "dameng") return "BINARY_DOUBLE";
       if (databaseType === "clickhouse") return "Float64";
diff --git a/crates/dbx-core/src/table_import.rs b/crates/dbx-core/src/table_import.rs
index ff7eeb034b..367fe79c7a 100644
--- a/crates/dbx-core/src/table_import.rs
+++ b/crates/dbx-core/src/table_import.rs
@@ -3575,6 +3575,7 @@ fn decimal_data_type(db_type: &DatabaseType) -> &'static str {
         | DatabaseType::Uxdb
         | DatabaseType::Kwdb
         | DatabaseType::Vastbase => "DOUBLE PRECISION",
+        DatabaseType::SqlServer => "FLOAT",
         DatabaseType::Sqlite | DatabaseType::Rqlite | DatabaseType::Turso | DatabaseType::CloudflareD1 => "REAL",
         DatabaseType::Oracle | DatabaseType::OceanbaseOracle | DatabaseType::Dameng => "BINARY_DOUBLE",
         DatabaseType::ClickHouse => "Float64",
@@ -8834,6 +8835,49 @@ mod tests {
         assert_eq!(plan.sql, "CREATE TABLE [dbo].[events] (\n  [notes] NVARCHAR(MAX)\n)");
     }
 
+    #[test]
+    fn create_table_plan_uses_sqlserver_float_for_inferred_decimals() {
+        let data = ParsedImportFile {
+            columns: vec![
+                "id".to_string(),
+                "active".to_string(),
+                "amount".to_string(),
+                "created_at".to_string(),
+                "notes".to_string(),
+            ],
+            rows: vec![vec![
+                serde_json::json!(1001),
+                serde_json::json!(true),
+                serde_json::json!("12.5"),
+                serde_json::json!("2026-07-07 08:15:00"),
+                serde_json::json!("invoice"),
+            ]],
+            total_rows: 1,
+            effective_encoding: None,
+        };
+        let mappings = data
+            .columns
+            .iter()
+            .map(|column| TableImportColumnMapping {
+                source_column: column.clone(),
+                target_column: column.clone(),
+                target_data_type: None,
+            })
+            .collect::<Vec<_>>();
+
+        let plan =
+            build_import_create_table_plan(&data, &mappings, "invoices", "dbo", &DatabaseType::SqlServer).unwrap();
+
+        assert_eq!(
+            plan.sql,
+            "CREATE TABLE [dbo].[invoices] (\n  [id] BIGINT,\n  [active] BIT,\n  [amount] FLOAT,\n  [created_at] DATETIME2,\n  [notes] NVARCHAR(MAX)\n)"
+        );
+        assert_eq!(decimal_data_type(&DatabaseType::Mysql), "DOUBLE");
+        assert_eq!(decimal_data_type(&DatabaseType::Postgres), "DOUBLE PRECISION");
+        assert_eq!(decimal_data_type(&DatabaseType::Sqlite), "REAL");
+        assert_eq!(decimal_data_type(&DatabaseType::Oracle), "BINARY_DOUBLE");
+    }
+
     #[test]
     fn create_table_plan_uses_user_defined_column_type() {
         let data = ParsedImportFile {