feat: abstracción DB multi-engine — CRUD genérico y openers para SQLite, Postgres, ClickHouse, DuckDB

Funciones Go con interfaz unificada para operaciones DB: open, close, create_table, exec, query, insert_row, insert_batch.
Openers específicos por engine. Tipo DBConfig para configuración común.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

functions/infra/clickhouse_open.go

@@ -0,0 +1,25 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+
+	_ "github.com/ClickHouse/clickhouse-go/v2"
+)
+
+// ClickHouseOpen connects to a ClickHouse server and returns a *sql.DB.
+// Constructs a DSN of the form:
+//
+//	clickhouse://user:password@host:port/database
+func ClickHouseOpen(host string, port int, user, password, database string) (*sql.DB, error) {
+	dsn := fmt.Sprintf("clickhouse://%s:%s@%s:%d/%s", user, password, host, port, database)
+	db, err := sql.Open("clickhouse", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("clickhouse_open: open: %w", err)
+	}
+	if err := db.Ping(); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("clickhouse_open: ping %s:%d/%s: %w", host, port, database, err)
+	}
+	return db, nil
+}

functions/infra/clickhouse_open.md

@@ -0,0 +1,37 @@
+---
+name: clickhouse_open
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func ClickHouseOpen(host string, port int, user, password, database string) (*sql.DB, error)"
+description: "Conecta a ClickHouse construyendo DSN clickhouse://user:pass@host:port/database."
+tags: [database, clickhouse, connection, sql, olap]
+uses_functions: []
+uses_types: [db_config_go_infra]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql", "github.com/ClickHouse/clickhouse-go/v2"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/clickhouse_open.go"
+---
+
+## Ejemplo
+
+```go
+db, err := ClickHouseOpen("localhost", 9000, "default", "", "analytics")
+if err != nil {
+    log.Fatal(err)
+}
+defer DBClose(db)
+
+rows, err := DBQuery(db, "SELECT event, count() FROM events GROUP BY event")
+```
+
+## Notas
+
+Usa el driver `github.com/ClickHouse/clickhouse-go/v2` registrado como "clickhouse". Puerto por defecto de ClickHouse es 9000 (nativo) o 8123 (HTTP). Hace ping al abrir para verificar conectividad.

functions/infra/db_close.go

@@ -0,0 +1,18 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+)
+
+// DBClose closes the database connection. Wraps db.Close() for composability
+// in pipelines that manage *sql.DB lifecycle explicitly.
+func DBClose(db *sql.DB) error {
+	if db == nil {
+		return fmt.Errorf("db_close: db is nil")
+	}
+	if err := db.Close(); err != nil {
+		return fmt.Errorf("db_close: %w", err)
+	}
+	return nil
+}

functions/infra/db_close.md

@@ -0,0 +1,35 @@
+---
+name: db_close
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func DBClose(db *sql.DB) error"
+description: "Cierra la conexion a la base de datos. Wrapper sobre db.Close() para composabilidad en pipelines que gestionan el ciclo de vida de *sql.DB explicitamente."
+tags: [database, sql, close, lifecycle]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/db_close.go"
+---
+
+## Ejemplo
+
+```go
+db, err := SQLiteOpen("/data/app.db")
+if err != nil {
+    return err
+}
+defer DBClose(db)
+```
+
+## Notas
+
+Retorna error si db es nil. En la mayoria de los casos se usa con `defer`. Existe como funcion del registry para que los pipelines puedan referenciarla en `uses_functions` y modelar el ciclo de vida completo de la conexion.

functions/infra/db_config.go

@@ -0,0 +1,8 @@
+package infra
+
+// DBConfig holds connection parameters for any supported database.
+type DBConfig struct {
+	Driver string            // "sqlite", "duckdb", "postgres", "clickhouse"
+	DSN    string            // Data source name / connection string
+	Opts   map[string]string // Driver-specific options (optional)
+}

functions/infra/db_create_table.go

@@ -0,0 +1,32 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+var validIdentifier = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_]*$`)
+
+// DBCreateTable executes CREATE TABLE IF NOT EXISTS for the given table with
+// the provided column definitions. Each element of columns should be a full
+// SQL column definition, e.g. "id INTEGER PRIMARY KEY" or "name TEXT NOT NULL".
+// Returns an error if the table name contains invalid characters.
+func DBCreateTable(db *sql.DB, table string, columns []string) error {
+	if !validIdentifier.MatchString(table) {
+		return fmt.Errorf("db_create_table: invalid table name %q (only alphanumeric and underscore allowed)", table)
+	}
+	if len(columns) == 0 {
+		return fmt.Errorf("db_create_table: at least one column definition required")
+	}
+	query := fmt.Sprintf(
+		"CREATE TABLE IF NOT EXISTS %s (%s)",
+		table,
+		strings.Join(columns, ", "),
+	)
+	if _, err := db.Exec(query); err != nil {
+		return fmt.Errorf("db_create_table %q: %w", table, err)
+	}
+	return nil
+}

functions/infra/db_create_table.md

@@ -0,0 +1,36 @@
+---
+name: db_create_table
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func DBCreateTable(db *sql.DB, table string, columns []string) error"
+description: "Ejecuta CREATE TABLE IF NOT EXISTS con las definiciones de columnas dadas. Valida que el nombre de tabla sea un identificador SQL seguro."
+tags: [database, sql, ddl, create, table, schema]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql", "regexp", "strings"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/db_create_table.go"
+---
+
+## Ejemplo
+
+```go
+err := DBCreateTable(db, "events", []string{
+    "id INTEGER PRIMARY KEY AUTOINCREMENT",
+    "name TEXT NOT NULL",
+    "ts  INTEGER NOT NULL",
+    "payload TEXT",
+})
+```
+
+## Notas
+
+`columns` son definiciones SQL completas incluyendo nombre, tipo y constraints. Usa `CREATE TABLE IF NOT EXISTS` para ser idempotente. Valida el nombre de tabla con regex `^[a-zA-Z_][a-zA-Z0-9_]*$` para prevenir SQL injection. Las definiciones de columna no se sanitizan — son responsabilidad del llamador.

functions/infra/db_exec.go

@@ -0,0 +1,22 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+)
+
+// DBExec executes a non-SELECT statement (INSERT, UPDATE, DELETE, DDL) and
+// returns the number of rows affected. For statements that don't return rows
+// affected (e.g. DDL on some drivers), the count may be 0.
+func DBExec(db *sql.DB, query string, args ...any) (int64, error) {
+	result, err := db.Exec(query, args...)
+	if err != nil {
+		return 0, fmt.Errorf("db_exec: %w", err)
+	}
+	n, err := result.RowsAffected()
+	if err != nil {
+		// Some drivers don't support RowsAffected; treat as 0.
+		return 0, nil
+	}
+	return n, nil
+}

functions/infra/db_exec.md

@@ -0,0 +1,35 @@
+---
+name: db_exec
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func DBExec(db *sql.DB, query string, args ...any) (int64, error)"
+description: "Ejecuta un statement no-SELECT (INSERT, UPDATE, DELETE, DDL) y retorna el numero de filas afectadas."
+tags: [database, sql, exec, insert, update, delete, ddl]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/db_exec.go"
+---
+
+## Ejemplo
+
+```go
+n, err := DBExec(db, "UPDATE users SET active = ? WHERE last_login < ?", false, cutoff)
+if err != nil {
+    return err
+}
+fmt.Printf("desactivados: %d usuarios\n", n)
+```
+
+## Notas
+
+Agnóstica al driver. Para DDL algunos drivers retornan 0 en RowsAffected — esto es normal. Para INSERT con last_insert_id usar `DBInsertRow` que retorna ese valor. Para multiples filas en una transaccion usar `DBInsertBatch`.

functions/infra/db_insert_batch.go

@@ -0,0 +1,70 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+	"strings"
+)
+
+// DBInsertBatch inserts multiple rows into a table using a prepared statement
+// inside a transaction. columns must match the order of values in each row.
+// Returns the total number of rows affected.
+// Column and table names are validated to contain only safe identifier chars.
+func DBInsertBatch(db *sql.DB, table string, columns []string, rows [][]any) (int64, error) {
+	if !validIdentifier.MatchString(table) {
+		return 0, fmt.Errorf("db_insert_batch: invalid table name %q", table)
+	}
+	if len(columns) == 0 {
+		return 0, fmt.Errorf("db_insert_batch: columns must not be empty")
+	}
+	if len(rows) == 0 {
+		return 0, nil
+	}
+
+	for _, col := range columns {
+		if !validIdentifier.MatchString(col) {
+			return 0, fmt.Errorf("db_insert_batch: invalid column name %q", col)
+		}
+	}
+
+	placeholders := make([]string, len(columns))
+	for i := range columns {
+		placeholders[i] = "?"
+	}
+	query := fmt.Sprintf(
+		"INSERT INTO %s (%s) VALUES (%s)",
+		table,
+		strings.Join(columns, ", "),
+		strings.Join(placeholders, ", "),
+	)
+
+	tx, err := db.Begin()
+	if err != nil {
+		return 0, fmt.Errorf("db_insert_batch: begin tx: %w", err)
+	}
+	defer tx.Rollback() //nolint:errcheck
+
+	stmt, err := tx.Prepare(query)
+	if err != nil {
+		return 0, fmt.Errorf("db_insert_batch: prepare: %w", err)
+	}
+	defer stmt.Close()
+
+	var total int64
+	for i, row := range rows {
+		if len(row) != len(columns) {
+			return 0, fmt.Errorf("db_insert_batch: row %d has %d values, expected %d", i, len(row), len(columns))
+		}
+		result, err := stmt.Exec(row...)
+		if err != nil {
+			return 0, fmt.Errorf("db_insert_batch: exec row %d: %w", i, err)
+		}
+		n, _ := result.RowsAffected()
+		total += n
+	}
+
+	if err := tx.Commit(); err != nil {
+		return 0, fmt.Errorf("db_insert_batch: commit: %w", err)
+	}
+	return total, nil
+}

functions/infra/db_insert_batch.md

@@ -0,0 +1,41 @@
+---
+name: db_insert_batch
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func DBInsertBatch(db *sql.DB, table string, columns []string, rows [][]any) (int64, error)"
+description: "Inserta multiples filas en una transaccion usando prepared statement. Retorna el total de filas afectadas. Mas eficiente que llamar DBInsertRow en un loop."
+tags: [database, sql, insert, batch, transaction, bulk]
+uses_functions: [db_insert_row_go_infra]
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql", "strings"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/db_insert_batch.go"
+---
+
+## Ejemplo
+
+```go
+cols := []string{"name", "score", "ts"}
+rows := [][]any{
+    {"Alice", 95.5, 1700000000},
+    {"Bob",   87.2, 1700000001},
+    {"Carol", 91.0, 1700000002},
+}
+n, err := DBInsertBatch(db, "results", cols, rows)
+if err != nil {
+    return err
+}
+fmt.Printf("insertadas: %d filas\n", n)
+```
+
+## Notas
+
+Usa `tx.Prepare()` + `stmt.Exec()` en un loop dentro de una transaccion. El rollback es automatico si alguna fila falla. Valida tabla y columnas con regex. Cada fila debe tener exactamente `len(columns)` valores — retorna error descriptivo si no coincide.

functions/infra/db_insert_row.go

@@ -0,0 +1,54 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// DBInsertRow generates and executes a single-row INSERT from a map of
+// column→value pairs. Returns the last insert ID reported by the driver.
+// Column and table names are validated to contain only safe identifier chars.
+func DBInsertRow(db *sql.DB, table string, row map[string]any) (int64, error) {
+	if !validIdentifier.MatchString(table) {
+		return 0, fmt.Errorf("db_insert_row: invalid table name %q", table)
+	}
+	if len(row) == 0 {
+		return 0, fmt.Errorf("db_insert_row: row map must not be empty")
+	}
+
+	// Sort keys for deterministic query generation.
+	cols := make([]string, 0, len(row))
+	for col := range row {
+		if !validIdentifier.MatchString(col) {
+			return 0, fmt.Errorf("db_insert_row: invalid column name %q", col)
+		}
+		cols = append(cols, col)
+	}
+	sort.Strings(cols)
+
+	placeholders := make([]string, len(cols))
+	values := make([]any, len(cols))
+	for i, col := range cols {
+		placeholders[i] = "?"
+		values[i] = row[col]
+	}
+
+	query := fmt.Sprintf(
+		"INSERT INTO %s (%s) VALUES (%s)",
+		table,
+		strings.Join(cols, ", "),
+		strings.Join(placeholders, ", "),
+	)
+
+	result, err := db.Exec(query, values...)
+	if err != nil {
+		return 0, fmt.Errorf("db_insert_row %q: %w", table, err)
+	}
+	id, err := result.LastInsertId()
+	if err != nil {
+		return 0, nil
+	}
+	return id, nil
+}

functions/infra/db_insert_row.md

@@ -0,0 +1,39 @@
+---
+name: db_insert_row
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func DBInsertRow(db *sql.DB, table string, row map[string]any) (int64, error)"
+description: "Genera y ejecuta un INSERT de una sola fila desde un map columna→valor. Retorna el last insert ID. Sanitiza nombres de tabla y columnas."
+tags: [database, sql, insert, row, dynamic]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql", "sort", "strings"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/db_insert_row.go"
+---
+
+## Ejemplo
+
+```go
+id, err := DBInsertRow(db, "users", map[string]any{
+    "name":   "Alice",
+    "email":  "alice@example.com",
+    "active": true,
+})
+if err != nil {
+    return err
+}
+fmt.Printf("nuevo usuario ID: %d\n", id)
+```
+
+## Notas
+
+Las claves del map se ordenan alfabeticamente para generar queries deterministas. Valida tabla y columnas con regex `^[a-zA-Z_][a-zA-Z0-9_]*$`. Para insertar muchas filas usar `DBInsertBatch` que es mas eficiente. El last insert ID puede ser 0 en drivers que no lo soportan (ej: postgres — usar RETURNING en su lugar con `DBQuery`).

functions/infra/db_query.go

@@ -0,0 +1,79 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+	"strconv"
+)
+
+// DBQuery executes a SELECT query and returns the results as a slice of maps.
+// Each map key is the column name; values are converted to native Go types:
+// int64, float64, bool, string, []byte, or nil for NULLs.
+func DBQuery(db *sql.DB, query string, args ...any) ([]map[string]any, error) {
+	rows, err := db.Query(query, args...)
+	if err != nil {
+		return nil, fmt.Errorf("db_query: %w", err)
+	}
+	defer rows.Close()
+
+	cols, err := rows.Columns()
+	if err != nil {
+		return nil, fmt.Errorf("db_query: columns: %w", err)
+	}
+	colTypes, err := rows.ColumnTypes()
+	if err != nil {
+		return nil, fmt.Errorf("db_query: column types: %w", err)
+	}
+
+	var results []map[string]any
+	for rows.Next() {
+		// Use RawBytes so we can inspect the raw value before converting.
+		raw := make([]sql.RawBytes, len(cols))
+		ptrs := make([]any, len(cols))
+		for i := range raw {
+			ptrs[i] = &raw[i]
+		}
+		if err := rows.Scan(ptrs...); err != nil {
+			return nil, fmt.Errorf("db_query: scan: %w", err)
+		}
+
+		row := make(map[string]any, len(cols))
+		for i, col := range cols {
+			if raw[i] == nil {
+				row[col] = nil
+				continue
+			}
+			row[col] = convertRaw(raw[i], colTypes[i].DatabaseTypeName())
+		}
+		results = append(results, row)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("db_query: rows: %w", err)
+	}
+	return results, nil
+}
+
+// convertRaw attempts to convert a raw SQL byte slice into a native Go type
+// based on the database column type name hint.
+func convertRaw(b sql.RawBytes, dbType string) any {
+	s := string(b)
+	switch dbType {
+	case "INTEGER", "INT", "BIGINT", "SMALLINT", "TINYINT", "INT2", "INT4", "INT8":
+		if v, err := strconv.ParseInt(s, 10, 64); err == nil {
+			return v
+		}
+	case "REAL", "FLOAT", "DOUBLE", "NUMERIC", "DECIMAL":
+		if v, err := strconv.ParseFloat(s, 64); err == nil {
+			return v
+		}
+	case "BOOLEAN", "BOOL":
+		if v, err := strconv.ParseBool(s); err == nil {
+			return v
+		}
+	case "BLOB":
+		cp := make([]byte, len(b))
+		copy(cp, b)
+		return cp
+	}
+	return s
+}

functions/infra/db_query.md

@@ -0,0 +1,37 @@
+---
+name: db_query
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func DBQuery(db *sql.DB, query string, args ...any) ([]map[string]any, error)"
+description: "Ejecuta un SELECT y retorna los resultados como slice de maps. Convierte valores a tipos nativos Go segun el tipo de columna reportado por el driver."
+tags: [database, sql, query, select, generic]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/db_query.go"
+---
+
+## Ejemplo
+
+```go
+rows, err := DBQuery(db, "SELECT id, name, score FROM players WHERE active = ?", true)
+if err != nil {
+    return err
+}
+for _, row := range rows {
+    fmt.Println(row["name"], row["score"])
+}
+```
+
+## Notas
+
+Agnóstica al driver — funciona con cualquier `*sql.DB` (sqlite, duckdb, postgres, clickhouse). Usa `sql.RawBytes` + `ColumnTypes()` para conversion dinamica. Convierte INTEGER→int64, FLOAT/REAL/DOUBLE→float64, BOOLEAN→bool, BLOB→[]byte, NULL→nil, resto→string. Para queries con muchos resultados considerar paginar con LIMIT/OFFSET.

functions/infra/duckdb_open.go

@@ -0,0 +1,27 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+
+	_ "github.com/marcboeker/go-duckdb"
+)
+
+// DuckDBOpen opens (or creates) a DuckDB database file.
+// Pass an empty path or ":memory:" for an in-memory database.
+// Returns a ready-to-use *sql.DB or an error.
+func DuckDBOpen(path string) (*sql.DB, error) {
+	dsn := path
+	if dsn == "" {
+		dsn = ":memory:"
+	}
+	db, err := sql.Open("duckdb", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("duckdb_open: open %q: %w", dsn, err)
+	}
+	if err := db.Ping(); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("duckdb_open: ping %q: %w", dsn, err)
+	}
+	return db, nil
+}

functions/infra/duckdb_open.md

@@ -0,0 +1,38 @@
+---
+name: duckdb_open
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func DuckDBOpen(path string) (*sql.DB, error)"
+description: "Abre (o crea) una base de datos DuckDB. Path vacio o ':memory:' abre una base en memoria."
+tags: [database, duckdb, connection, sql, analytics]
+uses_functions: []
+uses_types: [db_config_go_infra]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql", "github.com/marcboeker/go-duckdb"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/duckdb_open.go"
+---
+
+## Ejemplo
+
+```go
+// In-memory para analisis temporal
+db, err := DuckDBOpen("")
+if err != nil {
+    log.Fatal(err)
+}
+defer DBClose(db)
+
+rows, err := DBQuery(db, "SELECT * FROM read_parquet('/data/sales.parquet')")
+```
+
+## Notas
+
+Usa el driver `github.com/marcboeker/go-duckdb` (CGO). DuckDB es una base de datos OLAP embebida, ideal para analisis de datos. Path vacio equivale a `:memory:`. Hace ping al abrir para detectar errores temprano.

functions/infra/postgres_open.go

@@ -0,0 +1,32 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+// PostgresOpen connects to a PostgreSQL server and returns a *sql.DB.
+// sslmode defaults to "disable" when empty.
+// Constructs a DSN of the form:
+//
+//	host=<host> port=<port> user=<user> password=<password> dbname=<dbname> sslmode=<sslmode>
+func PostgresOpen(host string, port int, user, password, dbname string, sslmode string) (*sql.DB, error) {
+	if sslmode == "" {
+		sslmode = "disable"
+	}
+	dsn := fmt.Sprintf(
+		"host=%s port=%d user=%s password=%s dbname=%s sslmode=%s",
+		host, port, user, password, dbname, sslmode,
+	)
+	db, err := sql.Open("pgx", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("postgres_open: open: %w", err)
+	}
+	if err := db.Ping(); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("postgres_open: ping %s:%d/%s: %w", host, port, dbname, err)
+	}
+	return db, nil
+}

functions/infra/postgres_open.md

@@ -0,0 +1,37 @@
+---
+name: postgres_open
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func PostgresOpen(host string, port int, user, password, dbname string, sslmode string) (*sql.DB, error)"
+description: "Conecta a PostgreSQL construyendo el DSN desde parametros individuales. sslmode por defecto 'disable' si vacio."
+tags: [database, postgres, postgresql, connection, sql]
+uses_functions: []
+uses_types: [db_config_go_infra]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql", "github.com/jackc/pgx/v5/stdlib"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/postgres_open.go"
+---
+
+## Ejemplo
+
+```go
+db, err := PostgresOpen("localhost", 5432, "user", "secret", "mydb", "disable")
+if err != nil {
+    log.Fatal(err)
+}
+defer DBClose(db)
+
+rows, err := DBQuery(db, "SELECT id, name FROM users WHERE active = $1", true)
+```
+
+## Notas
+
+Usa el driver `github.com/jackc/pgx/v5/stdlib` registrado como "pgx". Construye DSN con los parametros separados para mayor legibilidad. Para produccion usar `sslmode=require` o `sslmode=verify-full`. Hace ping al abrir para verificar conectividad.

functions/infra/sqlite_open.go

@@ -0,0 +1,27 @@
+package infra
+
+import (
+	"database/sql"
+	"fmt"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+// SQLiteOpen opens (or creates) a SQLite database file with WAL mode and
+// foreign key support enabled. Returns a ready-to-use *sql.DB or an error.
+// Pass ":memory:" for an in-memory database.
+func SQLiteOpen(path string) (*sql.DB, error) {
+	if path == "" {
+		return nil, fmt.Errorf("sqlite_open: path must not be empty (use ':memory:' for in-memory)")
+	}
+	dsn := fmt.Sprintf("file:%s?_journal_mode=WAL&_foreign_keys=on", path)
+	db, err := sql.Open("sqlite3", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("sqlite_open: open %q: %w", path, err)
+	}
+	if err := db.Ping(); err != nil {
+		db.Close()
+		return nil, fmt.Errorf("sqlite_open: ping %q: %w", path, err)
+	}
+	return db, nil
+}

functions/infra/sqlite_open.md

@@ -0,0 +1,37 @@
+---
+name: sqlite_open
+kind: function
+lang: go
+domain: infra
+version: "1.0.0"
+purity: impure
+signature: "func SQLiteOpen(path string) (*sql.DB, error)"
+description: "Abre (o crea) una base de datos SQLite con WAL mode y foreign keys habilitados. Hace ping para verificar la conexion."
+tags: [database, sqlite, connection, sql]
+uses_functions: []
+uses_types: [db_config_go_infra]
+returns: []
+returns_optional: false
+error_type: "error_go_core"
+imports: ["database/sql", "github.com/mattn/go-sqlite3"]
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/infra/sqlite_open.go"
+---
+
+## Ejemplo
+
+```go
+db, err := SQLiteOpen("/data/myapp.db")
+if err != nil {
+    log.Fatal(err)
+}
+defer DBClose(db)
+
+rows, err := DBQuery(db, "SELECT * FROM users WHERE active = ?", 1)
+```
+
+## Notas
+
+Usa el driver `github.com/mattn/go-sqlite3` (CGO). El DSN incluye `_journal_mode=WAL` para mejor concurrencia y `_foreign_keys=on`. Acepta `:memory:` para base de datos en memoria. Hace ping al abrir para detectar errores temprano.

types/infra/db_config.md

@@ -0,0 +1,21 @@
+---
+name: db_config
+lang: go
+domain: infra
+version: "1.0.0"
+algebraic: product
+definition: |
+  type DBConfig struct {
+      Driver string            // "sqlite", "duckdb", "postgres", "clickhouse"
+      DSN    string            // Data source name / connection string
+      Opts   map[string]string // Driver-specific options (optional)
+  }
+description: "Parametros de conexion para cualquier base de datos soportada. Agnóstico al driver."
+tags: [database, config, connection, sqlite, duckdb, postgres, clickhouse]
+uses_types: []
+file_path: "functions/infra/db_config.go"
+---
+
+## Notas
+
+Tipo producto — todos los campos siempre presentes. Driver toma uno de los valores: "sqlite", "duckdb", "postgres", "clickhouse". DSN es el connection string nativo del driver. Opts permite pasar opciones adicionales especificas del driver sin necesidad de un tipo por driver.