feat(database): add MCP tool for fetching database schema #330 and closed #330

- Introduce `DatabaseMcpToolProvider` to handle fetching current database schema.
- Move `listSchemas` logic to `DatabaseSchemaAssistant` for reuse.
- Update `DatabaseFunctionProvider` to use `DatabaseSchemaAssistant.listSchemas`.

Author: phodal

exts/ext-database/src/main/kotlin/cc/unitmesh/database/provider/DatabaseFunctionProvider.kt

@@ -8,8 +8,6 @@ import cc.unitmesh.devti.devin.dataprovider.BuiltinCommand
 import cc.unitmesh.devti.provider.toolchain.ToolchainFunctionProvider
 import com.intellij.database.model.DasTable
 import com.intellij.database.model.RawDataSource
-import com.intellij.database.util.DasUtil
-import com.intellij.database.util.DbUtil
 import com.intellij.openapi.diagnostic.logger
 import com.intellij.openapi.project.Project
 
@@ -33,33 +31,13 @@ class DatabaseFunctionProvider : ToolchainFunctionProvider {
             ?: throw IllegalArgumentException("[Database]: Invalid Database function name")
 
         return when (databaseFunction) {
-            DatabaseFunction.Schema -> listSchemas(args, project)
+            DatabaseFunction.Schema -> DatabaseSchemaAssistant.listSchemas(project)
             DatabaseFunction.Table -> executeTableFunction(args, project)
             DatabaseFunction.Column -> executeColumnFunction(args, project)
             DatabaseFunction.Query -> executeSqlFunction(args, project)
         }
     }
 
-    private fun listSchemas(args: List<Any>, project: Project): String {
-        val dataSources = DbUtil.getDataSources(project)
-        if (dataSources.isEmpty) return "[Database]: No database found"
-
-        val dataItems = dataSources.mapNotNull {
-            val tableSchema = DasUtil.getTables(it).toList().mapNotNull<DasTable, String> {
-                if (it.dasParent?.name == "information_schema") return@mapNotNull null
-                getTableColumn(it)
-            }
-
-            if (tableSchema.isEmpty()) return@mapNotNull null
-            val name = it.name.substringBeforeLast('@')
-            "Database Schema result:\n\n```sql\n-- DATABASE NAME: ${name};\n${tableSchema.joinToString("\n")}\n```\n"
-        }
-
-        if (dataItems.isEmpty()) return "[Database]: No table found"
-
-        return dataItems.joinToString("\n")
-    }
-
     private fun executeTableFunction(args: List<Any>, project: Project): String {
         if (args.isEmpty()) {
             val dataSource = DatabaseSchemaAssistant.allRawDatasource(project).firstOrNull()
@@ -195,4 +173,4 @@ class DatabaseFunctionProvider : ToolchainFunctionProvider {
             ?: return emptyList()
         return DatabaseSchemaAssistant.getTableByDataSource(database)
     }
-}
+}

exts/ext-database/src/main/kotlin/cc/unitmesh/database/provider/DatabaseMcpToolProvider.kt

@@ -0,0 +1,20 @@
+package cc.unitmesh.database.provider
+
+import cc.unitmesh.database.util.DatabaseSchemaAssistant
+import cc.unitmesh.devti.mcp.AbstractMcpTool
+import cc.unitmesh.devti.mcp.NoArgs
+import cc.unitmesh.devti.mcp.Response
+import com.intellij.openapi.project.Project
+
+class DatabaseMcpToolProvider : AbstractMcpTool<NoArgs>() {
+    override val name: String = "get_current_database_schema"
+
+    override val description: String = """
+        Get the current database schema which connect in IntelliJ IDEA.
+    """.trimIndent()
+
+    override fun handle(project: Project, args: NoArgs): Response {
+        val listSchemas = DatabaseSchemaAssistant.listSchemas(project)
+        return Response(listSchemas)
+    }
+}

exts/ext-database/src/main/kotlin/cc/unitmesh/database/util/DatabaseSchemaAssistant.kt

@@ -6,12 +6,33 @@ import com.intellij.database.model.RawDataSource
 import com.intellij.database.psi.DbDataSource
 import com.intellij.database.psi.DbPsiFacade
 import com.intellij.database.util.DasUtil
+import com.intellij.database.util.DbUtil
 import com.intellij.openapi.project.Project
 import com.intellij.sql.isNullOr
 
 object DatabaseSchemaAssistant {
     fun getDataSources(project: Project): List<DbDataSource> = DbPsiFacade.getInstance(project).dataSources.toList()
 
+    fun listSchemas(project: Project): String {
+        val dataSources = DbUtil.getDataSources(project)
+        if (dataSources.isEmpty) return "[Database]: No database found"
+
+        val dataItems = dataSources.mapNotNull {
+            val tableSchema = DasUtil.getTables(it).toList().mapNotNull<DasTable, String> {
+                if (it.dasParent?.name == "information_schema") return@mapNotNull null
+                getTableColumn(it)
+            }
+
+            if (tableSchema.isEmpty()) return@mapNotNull null
+            val name = it.name.substringBeforeLast('@')
+            "Database Schema result:\n\n```sql\n-- DATABASE NAME: ${name};\n${tableSchema.joinToString("\n")}\n```\n"
+        }
+
+        if (dataItems.isEmpty()) return "[Database]: No table found"
+
+        return dataItems.joinToString("\n")
+    }
+
     fun allRawDatasource(project: Project): List<RawDataSource> {
         val dbPsiFacade = DbPsiFacade.getInstance(project)
         return dbPsiFacade.dataSources.map { dataSource ->

exts/ext-database/src/main/resources/cc.unitmesh.database.xml

@@ -38,5 +38,7 @@
         <livingDocumentation
                 language="Oracle"
                 implementationClass="cc.unitmesh.database.provider.SqlLivingDocumentationProvider"/>
+
+        <mcpTool implementation="cc.unitmesh.database.provider.DatabaseMcpToolProvider"/>
     </extensions>
 </idea-plugin>