diff --git a/apps/desktop/src/components/editor/SqlParameterDialog.vue b/apps/desktop/src/components/editor/SqlParameterDialog.vue
index faf4cf6343..f1da7b13a9 100644
--- a/apps/desktop/src/components/editor/SqlParameterDialog.vue
+++ b/apps/desktop/src/components/editor/SqlParameterDialog.vue
@@ -9,7 +9,7 @@ import { Popover, PopoverAnchor, PopoverContent } from "@/components/ui/popover"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 import TruncatedTextTooltip from "@/components/ui/TruncatedTextTooltip.vue";
 import { loadSqlParameterHistory, rememberSqlParameterValues } from "@/lib/sql/sqlParameterHistory";
-import { substituteSqlParameters, type SqlParameterInput, type SqlParameterValueKind } from "@/lib/sql/sqlParameters";
+import { substituteSqlParameters, type SqlParameterDescriptor, type SqlParameterInput, type SqlParameterSyntax, type SqlParameterValueKind } from "@/lib/sql/sqlParameters";
 import { useSqlHighlighter } from "@/composables/useSqlHighlighter";
 
 const { t } = useI18n();
@@ -19,7 +19,7 @@ const open = defineModel<boolean>("open", { default: false });
 
 const props = defineProps<{
   sql: string;
-  parameters: string[];
+  parameters: SqlParameterDescriptor[];
 }>();
 
 const emit = defineEmits<{
@@ -33,6 +33,14 @@ let closeHistoryTimer: ReturnType<typeof setTimeout> | undefined;
 
 const parameterKinds: SqlParameterValueKind[] = ["string", "number", "boolean", "null", "raw"];
 
+const syntaxLabels: Record<SqlParameterSyntax, string> = {
+  positional: "?",
+  named: ":name",
+  shell: "${name}",
+  mybatis: "#{name}",
+  sqlserver: "@name",
+};
+
 const resolvedSql = computed(() => substituteSqlParameters(props.sql, values.value));
 const highlightedSql = computed(() => highlight(resolvedSql.value));
 
@@ -42,10 +50,10 @@ watch(
     if (!isOpen) return;
     const next: Record<string, SqlParameterInput> = {};
     const nextHistories: Record<string, SqlParameterInput[]> = {};
-    for (const name of props.parameters) {
-      const history = loadSqlParameterHistory(name);
-      nextHistories[name] = history;
-      next[name] = values.value[name] ?? history[0] ?? { kind: "string", value: "" };
+    for (const parameter of props.parameters) {
+      const history = loadSqlParameterHistory(parameter.key);
+      nextHistories[parameter.key] = history;
+      next[parameter.key] = values.value[parameter.key] ?? history[0] ?? { kind: "string", value: "" };
     }
     values.value = next;
     histories.value = nextHistories;
@@ -111,15 +119,17 @@ function execute() {
         <p class="text-sm text-muted-foreground">{{ t("sqlParameters.description") }}</p>
 
         <div class="relative z-20 max-h-[302px] overflow-auto rounded-md border bg-background">
-          <div class="min-w-[580px]">
-            <div class="sticky top-0 z-10 grid grid-cols-[minmax(140px,1fr)_132px_minmax(180px,1.5fr)] border-b bg-muted px-3 py-2 text-xs font-medium text-muted-foreground">
+          <div class="min-w-[680px]">
+            <div class="sticky top-0 z-10 grid grid-cols-[minmax(140px,1fr)_104px_132px_minmax(180px,1.5fr)] border-b bg-muted px-3 py-2 text-xs font-medium text-muted-foreground">
               <div>{{ t("sqlParameters.name") }}</div>
+              <div>{{ t("sqlParameters.syntax") }}</div>
               <div>{{ t("sqlParameters.type") }}</div>
               <div>{{ t("sqlParameters.value") }}</div>
             </div>
-            <div v-for="name in parameters" :key="name" class="grid grid-cols-[minmax(140px,1fr)_132px_minmax(180px,1.5fr)] items-center gap-2 border-b px-3 py-2 text-sm last:border-b-0">
-              <div class="min-w-0 truncate font-mono text-xs">{{ name }}</div>
-              <Select :model-value="values[name]?.kind || 'string'" @update:model-value="(value) => updateKind(name, value as SqlParameterValueKind)">
+            <div v-for="parameter in parameters" :key="parameter.key" class="grid grid-cols-[minmax(140px,1fr)_104px_132px_minmax(180px,1.5fr)] items-center gap-2 border-b px-3 py-2 text-sm last:border-b-0">
+              <div class="min-w-0 truncate font-mono text-xs">{{ parameter.name }}</div>
+              <div class="min-w-0 truncate font-mono text-[11px] text-muted-foreground">{{ syntaxLabels[parameter.syntax] }}</div>
+              <Select :model-value="values[parameter.key]?.kind || 'string'" @update:model-value="(value) => updateKind(parameter.key, value as SqlParameterValueKind)">
                 <SelectTrigger class="h-8 bg-background text-xs">
                   <SelectValue />
                 </SelectTrigger>
@@ -130,28 +140,28 @@ function execute() {
                 </SelectContent>
               </Select>
               <div class="relative min-w-0">
-                <Popover :open="activeHistoryName === name && filteredSqlParameterHistory(name).length > 0">
+                <Popover :open="activeHistoryName === parameter.key && filteredSqlParameterHistory(parameter.key).length > 0">
                   <PopoverAnchor as-child>
                     <Input
-                      :model-value="values[name]?.value || ''"
+                      :model-value="values[parameter.key]?.value || ''"
                       class="h-8 bg-background font-mono text-xs"
-                      :disabled="values[name]?.kind === 'null'"
+                      :disabled="values[parameter.key]?.kind === 'null'"
                       autocomplete="off"
                       data-lpignore="true"
                       data-form-type="other"
                       :placeholder="t('sqlParameters.valuePlaceholder')"
-                      @focus="focusParameterInput(name, $event)"
-                      @blur="closeParameterHistory(name)"
-                      @update:model-value="(value) => updateValue(name, String(value))"
+                      @focus="focusParameterInput(parameter.key, $event)"
+                      @blur="closeParameterHistory(parameter.key)"
+                      @update:model-value="(value) => updateValue(parameter.key, String(value))"
                     />
                   </PopoverAnchor>
                   <PopoverContent align="start" side="bottom" class="z-[80] w-[var(--reka-popover-trigger-width)] max-h-40 gap-0 overflow-auto p-1" @open-auto-focus.prevent>
                     <button
-                      v-for="entry in filteredSqlParameterHistory(name)"
+                      v-for="entry in filteredSqlParameterHistory(parameter.key)"
                       :key="`${entry.kind}:${entry.value}`"
                       type="button"
                       class="flex w-full min-w-0 items-center justify-between gap-2 rounded px-2 py-1 text-left text-xs hover:bg-accent hover:text-accent-foreground"
-                      @mousedown.prevent="selectHistoryEntry(name, entry)"
+                      @mousedown.prevent="selectHistoryEntry(parameter.key, entry)"
                     >
                       <TruncatedTextTooltip :text="entry.value" class="min-w-0 flex-1 font-mono" side="top" :delay="150" />
                       <span class="shrink-0 text-[10px] uppercase text-muted-foreground">{{ t(`sqlParameters.kind.${entry.kind}`) }}</span>
diff --git a/apps/desktop/src/components/layout/AppDialogs.vue b/apps/desktop/src/components/layout/AppDialogs.vue
index 5d882148de..9f61bfdc2d 100644
--- a/apps/desktop/src/components/layout/AppDialogs.vue
+++ b/apps/desktop/src/components/layout/AppDialogs.vue
@@ -20,6 +20,7 @@ const DataGenerateDialog = defineAsyncComponent(() => import("@/components/gener
 import { useConnectionStore } from "@/stores/connectionStore";
 import { useDialogSources } from "@/composables/useDialogSources";
 import type { ConnectionDeepLinkDraft } from "@/lib/connection/connectionDeepLink";
+import type { SqlParameterDescriptor } from "@/lib/sql/sqlParameters";
 import type { ConfigTab } from "@/components/connection/ConnectionDialog.vue";
 
 const props = defineProps<{
@@ -31,7 +32,7 @@ const props = defineProps<{
   suppressDangerConfirm: boolean;
   showSqlParameterDialog: boolean;
   sqlParameterSourceSql: string;
-  sqlParameterNames: string[];
+  sqlParameterNames: SqlParameterDescriptor[];
 }>();
 
 const emit = defineEmits<{
diff --git a/apps/desktop/src/composables/useSqlExecution.ts b/apps/desktop/src/composables/useSqlExecution.ts
index 5bac5e381f..0a57f9d438 100644
--- a/apps/desktop/src/composables/useSqlExecution.ts
+++ b/apps/desktop/src/composables/useSqlExecution.ts
@@ -11,7 +11,7 @@ import { classifySqlActivityKind } from "@/lib/history/historyActivityKind";
 import { sqlMetadataRefreshTarget } from "@/lib/sql/sqlMetadataRefresh";
 import { classifyRedisCommandSafety, firstRedisCommandToken } from "@/lib/redis/redisCommandSafety";
 import { isSqlExecutionSnapshot, resolveExecutableSql, type SqlExecutionOverride, type SqlExecutionSnapshot } from "@/lib/sql/sqlExecutionTarget";
-import { extractSqlParameters } from "@/lib/sql/sqlParameters";
+import { extractSqlParameterDescriptors, type SqlParameterDescriptor } from "@/lib/sql/sqlParameters";
 import type { ConnectionConfig, QueryTab } from "@/types/database";
 
 const DANGER_RE = /^\s*(DROP|DELETE|TRUNCATE|ALTER|UPDATE|MERGE|REPLACE)\b/i;
@@ -60,7 +60,7 @@ export function useSqlExecution(deps: {
   const explainMode = ref<"explain" | "autotrace">("explain");
   const showSqlParameterDialog = ref(false);
   const sqlParameterSourceSql = ref("");
-  const sqlParameterNames = ref<string[]>([]);
+  const sqlParameterNames = ref<SqlParameterDescriptor[]>([]);
 
   async function resolvedExecutableSql(source?: SqlExecutionOverride): Promise<string> {
     if (typeof source === "string") return source;
@@ -107,7 +107,7 @@ export function useSqlExecution(deps: {
   }
 
   function prepareSqlParameterDialog(sql: string): boolean {
-    const parameters = extractSqlParameters(sql);
+    const parameters = extractSqlParameterDescriptors(sql);
     if (!parameters.length) return false;
     sqlParameterSourceSql.value = sql;
     sqlParameterNames.value = parameters;
diff --git a/apps/desktop/src/i18n/locales/en.ts b/apps/desktop/src/i18n/locales/en.ts
index a3148745f8..f1b3ddf10e 100644
--- a/apps/desktop/src/i18n/locales/en.ts
+++ b/apps/desktop/src/i18n/locales/en.ts
@@ -2124,6 +2124,7 @@ export default {
     title: "SQL Parameters",
     description: "Fill values for SQL template placeholders. DBX replaces them before executing the SQL.",
     name: "Parameter",
+    syntax: "Syntax",
     type: "Type",
     value: "Value",
     valuePlaceholder: "Enter value",
diff --git a/apps/desktop/src/i18n/locales/es.ts b/apps/desktop/src/i18n/locales/es.ts
index e2d5dfb957..d02238e521 100644
--- a/apps/desktop/src/i18n/locales/es.ts
+++ b/apps/desktop/src/i18n/locales/es.ts
@@ -2068,6 +2068,7 @@ export default withEnglishFallback({
     title: "Parámetros SQL",
     description: "Completa valores para marcadores de plantilla SQL. DBX los reemplaza antes de ejecutar el SQL.",
     name: "Parámetro",
+    syntax: "Sintaxis",
     type: "Tipo",
     value: "Valor",
     valuePlaceholder: "Introduce un valor",
diff --git a/apps/desktop/src/i18n/locales/it.ts b/apps/desktop/src/i18n/locales/it.ts
index e2bf839e69..6ad47c7a52 100644
--- a/apps/desktop/src/i18n/locales/it.ts
+++ b/apps/desktop/src/i18n/locales/it.ts
@@ -2066,6 +2066,7 @@ export default withEnglishFallback({
     title: "Parametri SQL",
     description: "Compila i valori per i segnaposto del template SQL. DBX li sostituisce prima di eseguire l'SQL.",
     name: "Parametro",
+    syntax: "Sintassi",
     type: "Tipo",
     value: "Valore",
     valuePlaceholder: "Inserisci valore",
diff --git a/apps/desktop/src/i18n/locales/ja.ts b/apps/desktop/src/i18n/locales/ja.ts
index 2ce41b2edb..1def0686e4 100644
--- a/apps/desktop/src/i18n/locales/ja.ts
+++ b/apps/desktop/src/i18n/locales/ja.ts
@@ -2066,6 +2066,7 @@ export default withEnglishFallback({
     title: "SQLパラメーター",
     description: "SQLテンプレートのプレースホルダーに値を入力します。DBXは実行前にSQLリテラルへ置換します。",
     name: "パラメーター",
+    syntax: "Syntax",
     type: "型",
     value: "値",
     valuePlaceholder: "値を入力",
diff --git a/apps/desktop/src/i18n/locales/pt-BR.ts b/apps/desktop/src/i18n/locales/pt-BR.ts
index 0f4f0b8805..aa53112898 100644
--- a/apps/desktop/src/i18n/locales/pt-BR.ts
+++ b/apps/desktop/src/i18n/locales/pt-BR.ts
@@ -2067,6 +2067,7 @@ export default withEnglishFallback({
     title: "Parâmetros SQL",
     description: "Preencha valores para marcadores de template SQL. O DBX substitui antes de executar o SQL.",
     name: "Parâmetro",
+    syntax: "Sintaxe",
     type: "Tipo",
     value: "Valor",
     valuePlaceholder: "Digite o valor",
diff --git a/apps/desktop/src/i18n/locales/zh-CN.ts b/apps/desktop/src/i18n/locales/zh-CN.ts
index fe58b0f139..bc9179817e 100644
--- a/apps/desktop/src/i18n/locales/zh-CN.ts
+++ b/apps/desktop/src/i18n/locales/zh-CN.ts
@@ -2124,6 +2124,7 @@ export default withEnglishFallback({
     title: "SQL 参数",
     description: "为 SQL 模板占位符填写参数值，DBX 会在执行前替换为 SQL 字面量。",
     name: "参数名",
+    syntax: "Syntax",
     type: "类型",
     value: "参数值",
     valuePlaceholder: "输入参数值",
diff --git a/apps/desktop/src/i18n/locales/zh-TW.ts b/apps/desktop/src/i18n/locales/zh-TW.ts
index 6fc9ecf7e0..6a7ba99b78 100644
--- a/apps/desktop/src/i18n/locales/zh-TW.ts
+++ b/apps/desktop/src/i18n/locales/zh-TW.ts
@@ -1970,6 +1970,7 @@ export default withEnglishFallback({
     title: "SQL 參數",
     description: "為 SQL 模板佔位符填寫參數值，DBX 會在執行前替換為 SQL 字面量。",
     name: "參數名",
+    syntax: "Syntax",
     type: "類型",
     value: "參數值",
     valuePlaceholder: "輸入參數值",
diff --git a/apps/desktop/src/lib/__tests__/sql/sqlParameters.spec.ts b/apps/desktop/src/lib/__tests__/sql/sqlParameters.spec.ts
index 420a3cf7dd..9ee979a65b 100644
--- a/apps/desktop/src/lib/__tests__/sql/sqlParameters.spec.ts
+++ b/apps/desktop/src/lib/__tests__/sql/sqlParameters.spec.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { extractSqlParameters, sqlParameterLiteral, substituteSqlParameters } from "@/lib/sql/sqlParameters";
+import { extractSqlParameterDescriptors, extractSqlParameters, sqlParameterLiteral, substituteSqlParameters } from "@/lib/sql/sqlParameters";
 
 describe("extractSqlParameters", () => {
   it("extracts unique template parameters in order", () => {
@@ -23,6 +23,43 @@ describe("extractSqlParameters", () => {
     const sql = "select $$ ${body_param} $$, $tag$ ${tag_param} $tag$, ${real_param}";
     expect(extractSqlParameters(sql)).toEqual(["real_param"]);
   });
+
+  it("extracts supported placeholder syntaxes in order", () => {
+    const sql = "select ? as a, :named as b, ${shell_name} as c, #{mybatis_name} as d, @sql_server_name as e";
+    expect(extractSqlParameters(sql)).toEqual(["?1", "named", "shell_name", "mybatis_name", "sql_server_name"]);
+  });
+
+  it("describes each placeholder syntax for the parameter dialog", () => {
+    const sql = "select ? as a, :named as b, ${shell_name} as c, #{mybatis_name} as d, @sql_server_name as e";
+    expect(extractSqlParameterDescriptors(sql)).toEqual([
+      { key: "?1", name: "?1", syntax: "positional", token: "?" },
+      { key: "named", name: "named", syntax: "named", token: ":named" },
+      { key: "shell_name", name: "shell_name", syntax: "shell", token: "${shell_name}" },
+      { key: "mybatis_name", name: "mybatis_name", syntax: "mybatis", token: "#{mybatis_name}" },
+      { key: "sql_server_name", name: "sql_server_name", syntax: "sqlserver", token: "@sql_server_name" },
+    ]);
+  });
+
+  it("ignores declared SQL Server variables and system variables", () => {
+    const sql = `
+      declare @id int = 1, @name nvarchar(50);
+      select @@version, @id, @name, @input_value
+    `;
+    expect(extractSqlParameters(sql)).toEqual(["input_value"]);
+  });
+
+  it("stops SQL Server declaration scanning when a new statement starts without a semicolon", () => {
+    const sql = `
+      declare @id int = 1
+      select @id, @tenant_id
+    `;
+    expect(extractSqlParameters(sql)).toEqual(["tenant_id"]);
+  });
+
+  it("does not treat PostgreSQL casts or assignment operators as named parameters", () => {
+    const sql = "select value::int, value := 1, :actual_value";
+    expect(extractSqlParameters(sql)).toEqual(["actual_value"]);
+  });
 });
 
 describe("substituteSqlParameters", () => {
@@ -47,6 +84,35 @@ describe("substituteSqlParameters", () => {
       }),
     ).toBe("select 'O''Reilly', NULL, current_date");
   });
+
+  it("replaces all supported placeholder syntaxes with SQL literals", () => {
+    const sql = "select ? as a, :named as b, ${shell_name} as c, #{mybatis_name} as d, @sql_server_name as e";
+    expect(
+      substituteSqlParameters(sql, {
+        "?1": { kind: "number", value: "42" },
+        named: { kind: "string", value: "alpha" },
+        shell_name: { kind: "boolean", value: "yes" },
+        mybatis_name: { kind: "null", value: "" },
+        sql_server_name: { kind: "raw", value: "current_timestamp" },
+      }),
+    ).toBe("select 42 as a, 'alpha' as b, TRUE as c, NULL as d, current_timestamp as e");
+  });
+
+  it("replaces repeated named placeholders once and positional placeholders independently", () => {
+    const sql = "select :name, :name, ?, ?";
+    expect(
+      substituteSqlParameters(sql, {
+        name: { kind: "string", value: "same" },
+        "?1": { kind: "number", value: "1" },
+        "?2": { kind: "number", value: "2" },
+      }),
+    ).toBe("select 'same', 'same', 1, 2");
+  });
+
+  it("leaves declared SQL Server variables untouched while replacing undeclared variables", () => {
+    const sql = "DECLARE @id int = 1; SELECT * FROM users WHERE id = @id AND tenant_id = @tenant_id";
+    expect(substituteSqlParameters(sql, { tenant_id: { kind: "number", value: "7" } })).toBe("DECLARE @id int = 1; SELECT * FROM users WHERE id = @id AND tenant_id = 7");
+  });
 });
 
 describe("sqlParameterLiteral", () => {
diff --git a/apps/desktop/src/lib/sql/sqlParameters.ts b/apps/desktop/src/lib/sql/sqlParameters.ts
index 607d2aa823..f718ede487 100644
--- a/apps/desktop/src/lib/sql/sqlParameters.ts
+++ b/apps/desktop/src/lib/sql/sqlParameters.ts
@@ -5,20 +5,42 @@ export interface SqlParameterInput {
   value: string;
 }
 
-interface ParameterOccurrence {
+export type SqlParameterSyntax = "positional" | "named" | "shell" | "mybatis" | "sqlserver";
+
+export interface SqlParameterDescriptor {
+  key: string;
   name: string;
+  syntax: SqlParameterSyntax;
+  token: string;
+}
+
+interface ParameterOccurrence extends SqlParameterDescriptor {
   start: number;
   end: number;
 }
 
 const PARAMETER_NAME_RE = /^[\p{L}_][\p{L}\p{N}_]*$/u;
+const PARAMETER_NAME_START_RE = /[\p{L}_]/u;
+const PARAMETER_NAME_CHAR_RE = /[\p{L}\p{N}_]/u;
 
 export function extractSqlParameters(sql: string): string[] {
+  return extractSqlParameterDescriptors(sql).map((descriptor) => descriptor.key);
+}
+
+export function extractSqlParameterDescriptors(sql: string): SqlParameterDescriptor[] {
   const names = new Set<string>();
+  const descriptors: SqlParameterDescriptor[] = [];
   for (const occurrence of findSqlParameterOccurrences(sql)) {
-    names.add(occurrence.name);
+    if (names.has(occurrence.key)) continue;
+    names.add(occurrence.key);
+    descriptors.push({
+      key: occurrence.key,
+      name: occurrence.name,
+      syntax: occurrence.syntax,
+      token: occurrence.token,
+    });
   }
-  return [...names];
+  return descriptors;
 }
 
 export function substituteSqlParameters(sql: string, values: Record<string, SqlParameterInput>): string {
@@ -29,7 +51,7 @@ export function substituteSqlParameters(sql: string, values: Record<string, SqlP
   let cursor = 0;
   for (const occurrence of occurrences) {
     result += sql.slice(cursor, occurrence.start);
-    result += sqlParameterLiteral(values[occurrence.name] ?? { kind: "string", value: "" });
+    result += sqlParameterLiteral(values[occurrence.key] ?? { kind: "string", value: "" });
     cursor = occurrence.end;
   }
   result += sql.slice(cursor);
@@ -47,8 +69,10 @@ export function sqlParameterLiteral(input: SqlParameterInput): string {
 
 function findSqlParameterOccurrences(sql: string): ParameterOccurrence[] {
   const occurrences: ParameterOccurrence[] = [];
+  const declaredSqlServerVariables = collectDeclaredSqlServerVariables(sql);
   let i = 0;
   let dollarQuoteEnd = "";
+  let positionalIndex = 0;
 
   while (i < sql.length) {
     if (dollarQuoteEnd) {
@@ -74,25 +98,73 @@ function findSqlParameterOccurrences(sql: string): ParameterOccurrence[] {
       i = skipLine(sql, i + 2);
       continue;
     }
-    if (ch === "#") {
-      i = skipLine(sql, i + 1);
-      continue;
-    }
     if (ch === "/" && next === "*") {
       i = skipBlockComment(sql, i + 2);
       continue;
     }
+    if (ch === "?") {
+      positionalIndex += 1;
+      const key = `?${positionalIndex}`;
+      occurrences.push({ key, name: key, syntax: "positional", token: "?", start: i, end: i + 1 });
+      i += 1;
+      continue;
+    }
+    if (ch === ":") {
+      const name = readParameterName(sql, i + 1);
+      if (name && sql[i - 1] !== ":" && sql[i + 1] !== "=") {
+        occurrences.push({
+          key: name,
+          name,
+          syntax: "named",
+          token: sql.slice(i, i + 1 + name.length),
+          start: i,
+          end: i + 1 + name.length,
+        });
+        i += 1 + name.length;
+        continue;
+      }
+    }
     if (ch === "$" && next === "{") {
       const end = sql.indexOf("}", i + 2);
       if (end !== -1) {
         const name = sql.slice(i + 2, end).trim();
         if (PARAMETER_NAME_RE.test(name)) {
-          occurrences.push({ name, start: i, end: end + 1 });
+          occurrences.push({ key: name, name, syntax: "shell", token: sql.slice(i, end + 1), start: i, end: end + 1 });
           i = end + 1;
           continue;
         }
       }
     }
+    if (ch === "#" && next === "{") {
+      const end = sql.indexOf("}", i + 2);
+      if (end !== -1) {
+        const name = sql.slice(i + 2, end).trim();
+        if (PARAMETER_NAME_RE.test(name)) {
+          occurrences.push({ key: name, name, syntax: "mybatis", token: sql.slice(i, end + 1), start: i, end: end + 1 });
+          i = end + 1;
+          continue;
+        }
+      }
+    }
+    if (ch === "#") {
+      i = skipLine(sql, i + 1);
+      continue;
+    }
+    if (ch === "@") {
+      const name = readParameterName(sql, i + 1);
+      if (name && next !== "@" && sql[i - 1] !== "@" && !declaredSqlServerVariables.has(name.toLowerCase())) {
+        occurrences.push({
+          key: name,
+          name,
+          syntax: "sqlserver",
+          token: sql.slice(i, i + 1 + name.length),
+          start: i,
+          end: i + 1 + name.length,
+        });
+        i += 1 + name.length;
+        continue;
+      }
+    }
     if (ch === "$") {
       const marker = readDollarQuoteMarker(sql, i);
       if (marker) {
@@ -107,6 +179,123 @@ function findSqlParameterOccurrences(sql: string): ParameterOccurrence[] {
   return occurrences;
 }
 
+function collectDeclaredSqlServerVariables(sql: string): Set<string> {
+  const declared = new Set<string>();
+  let i = 0;
+  let dollarQuoteEnd = "";
+
+  while (i < sql.length) {
+    if (dollarQuoteEnd) {
+      const end = sql.indexOf(dollarQuoteEnd, i);
+      if (end === -1) break;
+      i = end + dollarQuoteEnd.length;
+      dollarQuoteEnd = "";
+      continue;
+    }
+
+    const ch = sql[i];
+    const next = sql[i + 1];
+    if (ch === "'" || ch === '"' || ch === "`") {
+      i = skipQuoted(sql, i, ch);
+      continue;
+    }
+    if (ch === "[") {
+      i = skipBracketIdentifier(sql, i);
+      continue;
+    }
+    if (ch === "-" && next === "-") {
+      i = skipLine(sql, i + 2);
+      continue;
+    }
+    if (ch === "/" && next === "*") {
+      i = skipBlockComment(sql, i + 2);
+      continue;
+    }
+    if (ch === "$") {
+      const marker = readDollarQuoteMarker(sql, i);
+      if (marker) {
+        dollarQuoteEnd = marker;
+        i += marker.length;
+        continue;
+      }
+    }
+    if (ch === "#") {
+      i = skipLine(sql, i + 1);
+      continue;
+    }
+    if (matchesWord(sql, i, "declare")) {
+      i = collectDeclareStatementVariables(sql, i + "declare".length, declared);
+      continue;
+    }
+    i += 1;
+  }
+
+  return declared;
+}
+
+function collectDeclareStatementVariables(sql: string, start: number, declared: Set<string>): number {
+  let i = start;
+  while (i < sql.length) {
+    const ch = sql[i];
+    const next = sql[i + 1];
+    if (ch === ";") return i + 1;
+    if (isLineStatementStart(sql, i) && isSqlStatementKeyword(sql, i)) return i;
+    if (ch === "'" || ch === '"' || ch === "`") {
+      i = skipQuoted(sql, i, ch);
+      continue;
+    }
+    if (ch === "[") {
+      i = skipBracketIdentifier(sql, i);
+      continue;
+    }
+    if (ch === "-" && next === "-") {
+      i = skipLine(sql, i + 2);
+      continue;
+    }
+    if (ch === "/" && next === "*") {
+      i = skipBlockComment(sql, i + 2);
+      continue;
+    }
+    if (ch === "#") {
+      i = skipLine(sql, i + 1);
+      continue;
+    }
+    if (ch === "@") {
+      const name = readParameterName(sql, i + 1);
+      if (name && next !== "@" && sql[i - 1] !== "@") {
+        declared.add(name.toLowerCase());
+        i += 1 + name.length;
+        continue;
+      }
+    }
+    i += 1;
+  }
+  return i;
+}
+
+function isLineStatementStart(sql: string, start: number): boolean {
+  let i = start - 1;
+  while (i >= 0 && (sql[i] === " " || sql[i] === "\t" || sql[i] === "\r")) i -= 1;
+  return i >= 0 && sql[i] === "\n";
+}
+
+function isSqlStatementKeyword(sql: string, start: number): boolean {
+  return ["select", "with", "insert", "update", "delete", "merge", "exec", "execute", "set", "if", "while", "begin", "create", "alter", "drop", "truncate"].some((keyword) => matchesWord(sql, start, keyword));
+}
+
+function matchesWord(sql: string, start: number, word: string): boolean {
+  const value = sql.slice(start, start + word.length);
+  if (value.toLowerCase() !== word) return false;
+  return !PARAMETER_NAME_CHAR_RE.test(sql[start - 1] ?? "") && !PARAMETER_NAME_CHAR_RE.test(sql[start + word.length] ?? "");
+}
+
+function readParameterName(sql: string, start: number): string {
+  if (!PARAMETER_NAME_START_RE.test(sql[start] ?? "")) return "";
+  let i = start + 1;
+  while (i < sql.length && PARAMETER_NAME_CHAR_RE.test(sql[i])) i += 1;
+  return sql.slice(start, i);
+}
+
 function skipQuoted(sql: string, start: number, quote: string): number {
   let i = start + 1;
   while (i < sql.length) {