check if datbase is initialized before display schema, index and tables

cli/app.rs

@@ -945,6 +945,15 @@ impl Limbo {
     }
 
     fn display_schema(&mut self, table: Option<&str>) -> anyhow::Result<()> {
+        if !self.conn.is_db_initialized() {
+            if let Some(table_name) = table {
+                self.write_fmt(format_args!("-- Error: Table '{table_name}' not found."))?;
+            } else {
+                self.writeln("-- No tables or indexes found in the database.")?;
+            }
+            return Ok(());
+        }
+
         let sql = match table {
         Some(table_name) => format!(
             "SELECT sql FROM sqlite_schema WHERE type IN ('table', 'index') AND tbl_name = '{table_name}' AND name NOT LIKE 'sqlite_%'"
@@ -1002,6 +1011,15 @@ impl Limbo {
     }
 
     fn display_indexes(&mut self, maybe_table: Option<String>) -> anyhow::Result<()> {
+        if !self.conn.is_db_initialized() {
+            if let Some(tbl_name) = &maybe_table {
+                self.write_fmt(format_args!("-- Error: Table '{tbl_name}' not found."))?;
+            } else {
+                self.writeln("-- No indexes found in the database.")?;
+            }
+            return Ok(());
+        }
+
         let sql = match maybe_table {
             Some(ref tbl_name) => format!(
                 "SELECT name FROM sqlite_schema WHERE type='index' AND tbl_name = '{tbl_name}' ORDER BY 1"
@@ -1050,6 +1068,17 @@ impl Limbo {
     }
 
     fn display_tables(&mut self, pattern: Option<&str>) -> anyhow::Result<()> {
+        if !self.conn.is_db_initialized() {
+            if let Some(pattern) = pattern {
+                self.write_fmt(format_args!(
+                    "-- Error: Tables with pattern '{pattern}' not found."
+                ))?;
+            } else {
+                self.writeln("-- No tables found in the database.")?;
+            }
+            return Ok(());
+        }
+
         let sql = match pattern {
             Some(pattern) => format!(
                 "SELECT name FROM sqlite_schema WHERE type='table' AND name NOT LIKE 'sqlite_%' AND name LIKE '{pattern}' ORDER BY 1"

core/lib.rs

@@ -1167,6 +1167,10 @@ impl Connection {
         let schema = Arc::make_mut(&mut *schema_ref);
         f(schema)
     }
+
+    pub fn is_db_initialized(&self) -> bool {
+        self._db.db_state.is_initialized()
+    }
 }
 
 pub struct Statement {