Merge pull request 'v0.5.0-add_llmutils' (#12) from v0.5.0-add_llmutils into main

Reviewed-on: #12

Project.toml

@@ -1,6 +1,6 @@
 name = "GeneralUtils"
 uuid = "c6c72f09-b708-4ac8-ac7c-2084d70108fe"
-version = "0.5.0"
+version = "0.5.1"
 authors = ["tonaerospace <tonaerospace.etc@gmail.com>"]
 
 [deps]

src/llmUtil.jl

@@ -3,7 +3,7 @@ module llmUtil
 export formatLLMtext, extractthink, checkAgentResponse_JSON, clean_json_response,
         extract_column_metadata, generate_embedding_payloads, resolve_semantic_cluster,
         harvest_entity_catalog, resolve_entity, harvest_db_undirected_schema_graph,
-        get_db_table_schema
+        get_db_table_schema, get_db_table_schema_simple
 
 using UUIDs, JSON, Dates, DataFrames, StringDistances, Graphs, LibPQ
 using ..util
@@ -1016,7 +1016,115 @@ function get_db_table_schema(conn::LibPQ.Connection, table_name::String)::DataFr
 end
 
 
+""" Generate simplified DDL statement for a PostgreSQL table.
 
+Extracts table structure from PostgreSQL and returns a clean CREATE TABLE statement
+without NULL/NOT NULL constraints, useful for schema documentation or migration purposes.
+
+# Arguments
+- `conn::LibPQ.Connection`
+  A PostgreSQL connection object created via `LibPQ.Connection()`.
+- `table_name::String`
+  The name of the table to extract.
+- `schema_name::String` (default: `"public"`)
+  The schema containing the table.
+
+# Return
+- `String`
+  A CREATE TABLE DDL statement containing:
+  - Column definitions with names, types, and DEFAULT values
+  - Table-level constraints (PRIMARY KEY, FOREIGN KEY, UNIQUE, CHECK)
+  - Excludes NULL/NOT NULL specifications for cleaner output
+
+# Details
+The function:
+1. Queries PostgreSQL system catalogs (`pg_attribute`, `pg_class`, `pg_namespace`)
+2. Extracts column names, data types, and default values
+3. Captures table-level constraints via `pg_constraint`
+4. Omits NULL/NOT NULL checks to produce a simplified schema definition
+5. Returns properly formatted DDL with quoted identifiers
+
+# Example
+```julia
+julia> using GeneralUtils, LibPQ
+julia> conn = LibPQ.Connection("host=localhost port=5432 dbname=winedb user=admin password=secret")
+julia> ddl = GeneralUtils.get_db_table_schema_simple(conn, "wine")
+"CREATE TABLE \"public\".\"wine\" (
+    \"id\" integer DEFAULT nextval('wine_id_seq'::regclass),
+    \"wine_name\" text,
+    \"year\" integer,
+    \"price\" numeric
+);"
+```
+"""
+function get_db_table_schema_simple(pg_conn_str::String, table_name::String; 
+  schema_name::String="public")::String
+  conn = LibPQ.Connection(pg_conn_str)
+  return get_db_table_schema_simple(conn, table_name; schema_name=schema_name)
+end
+
+function get_db_table_schema_simple(conn, table_name::String; schema_name::String="public")::String
+    # 1. SQL query tailored to omit nullability checks
+    sql = """
+    SELECT 
+        a.attname AS column_name,
+        format_type(a.atttypid, a.atttypmod) AS data_type,
+        pg_get_expr(def.adbin, def.adrelid) AS default_value,
+        COALESCE(
+            (SELECT pg_get_constraintdef(p.oid) 
+             FROM pg_catalog.pg_constraint p 
+             WHERE p.conrelid = c.oid AND a.attnum = ANY(p.conkey) 
+             LIMIT 1), ''
+        ) AS constraint_definition
+    FROM 
+        pg_catalog.pg_attribute a
+    JOIN 
+        pg_catalog.pg_class c ON a.attrelid = c.oid
+    JOIN 
+        pg_catalog.pg_namespace n ON c.relnamespace = n.oid
+    LEFT JOIN 
+        pg_catalog.pg_attrdef def ON def.adrelid = c.oid AND def.adnum = a.attnum
+    WHERE 
+        c.relname = \$1
+        AND n.nspname = \$2
+        AND a.attnum > 0 
+        AND NOT a.attisdropped
+    ORDER BY 
+        a.attnum;
+    """
+
+    result = execute(conn, sql, [table_name, schema_name])
+    
+    if length(result) == 0
+        error("Table '$schema_name.$table_name' not found.")
+    end
+
+    ddl_lines = String[]
+    constraints = String[]
+
+    for row in result
+        col_name   = row.column_name
+        data_type  = row.data_type
+        
+        # Handle the default value if it exists
+        default_val = ismissing(row.default_value) ? "" : " DEFAULT " * row.default_value
+        
+        # Build the column definition line (without NULL/NOT NULL)
+        col_def = "    \"$col_name\" $data_type$default_val"
+        push!(ddl_lines, col_def)
+
+        # Handle table-level constraints
+        con_def = ismissing(row.constraint_definition) ? "" : row.constraint_definition
+        if !isempty(con_def) && !(con_def in constraints)
+            push!(constraints, "    " * con_def)
+        end
+    end
+
+    all_definitions = vcat(ddl_lines, constraints)
+    body = join(all_definitions, ",\n")
+    
+    return "CREATE TABLE \"$schema_name\".\"$table_name\" (\n$body\n);"
+end