feat: add sql agent (#152)

agents/sql/tools.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+
+set -e
+
+ROOT_DIR="${LLM_ROOT_DIR:-$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)}"
+
+# @meta require-tools usql
+# @env LLM_AGENT_VAR_DSN! The database connection url. e.g. pgsql://user:pass@host:port 
+
+# @cmd Execute a SELECT query
+# @option --query!                  SELECT SQL query to execute
+read_query() {
+    if ! grep -qi '^select' <<<"$argc_query"; then
+        echo "error: only SELECT query is allowed" >&2
+        exit 1
+    fi
+    _run_sql "$argc_query"
+}
+
+# @cmd Execute an SQL query
+# @option --query!                  SQL query to execute
+write_query() {
+    "$ROOT_DIR/utils/guard_operation.sh" "Execute SQL?"
+    _run_sql "$argc_query"
+}
+
+# @cmd List all tables
+list_tables() {
+    _run_sql "\dt+"
+}
+
+# @cmd Get the schema information for a specific table
+# @option --table-name!             Name of the table to describe
+describe_table() {
+    _run_sql "\d $argc_table_name"
+}
+
+_run_sql() {
+    usql "$LLM_AGENT_VAR_DSN" -c "$1" >> "$LLM_OUTPUT"
+}
+
+# See more details at https://github.com/sigoden/argc
+eval "$(argc --argc-eval "$0" "$@")"