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relspecgo/pkg/readers/pgsql/reader.go
Hein 5e1448dcdb
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sql writer
2025-12-17 20:44:02 +02:00

348 lines
9.7 KiB
Go

package pgsql
import (
"context"
"fmt"
"github.com/jackc/pgx/v5"
"git.warky.dev/wdevs/relspecgo/pkg/models"
"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
"git.warky.dev/wdevs/relspecgo/pkg/readers"
)
// Reader implements the readers.Reader interface for PostgreSQL databases
type Reader struct {
options *readers.ReaderOptions
conn *pgx.Conn
ctx context.Context
}
// NewReader creates a new PostgreSQL reader
func NewReader(options *readers.ReaderOptions) *Reader {
return &Reader{
options: options,
ctx: context.Background(),
}
}
// ReadDatabase reads the entire database schema from PostgreSQL
func (r *Reader) ReadDatabase() (*models.Database, error) {
// Validate connection string
if r.options.ConnectionString == "" {
return nil, fmt.Errorf("connection string is required")
}
// Connect to the database
if err := r.connect(); err != nil {
return nil, fmt.Errorf("failed to connect: %w", err)
}
defer r.close()
// Get database name from connection
var dbName string
err := r.conn.QueryRow(r.ctx, "SELECT current_database()").Scan(&dbName)
if err != nil {
return nil, fmt.Errorf("failed to get database name: %w", err)
}
// Initialize database model
db := models.InitDatabase(dbName)
db.DatabaseType = models.PostgresqlDatabaseType
db.SourceFormat = "pgsql"
// Get PostgreSQL version
var version string
err = r.conn.QueryRow(r.ctx, "SELECT version()").Scan(&version)
if err == nil {
db.DatabaseVersion = version
}
// Query all schemas
schemas, err := r.querySchemas()
if err != nil {
return nil, fmt.Errorf("failed to query schemas: %w", err)
}
// Process each schema
for _, schema := range schemas {
// Query tables for this schema
tables, err := r.queryTables(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query tables for schema %s: %w", schema.Name, err)
}
schema.Tables = tables
// Query views for this schema
views, err := r.queryViews(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query views for schema %s: %w", schema.Name, err)
}
schema.Views = views
// Query sequences for this schema
sequences, err := r.querySequences(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query sequences for schema %s: %w", schema.Name, err)
}
schema.Sequences = sequences
// Query columns for tables and views
columnsMap, err := r.queryColumns(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query columns for schema %s: %w", schema.Name, err)
}
// Populate table columns
for _, table := range schema.Tables {
tableKey := schema.Name + "." + table.Name
if cols, exists := columnsMap[tableKey]; exists {
table.Columns = cols
}
}
// Populate view columns
for _, view := range schema.Views {
viewKey := schema.Name + "." + view.Name
if cols, exists := columnsMap[viewKey]; exists {
view.Columns = cols
}
}
// Query primary keys
primaryKeys, err := r.queryPrimaryKeys(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query primary keys for schema %s: %w", schema.Name, err)
}
// Apply primary keys to tables
for _, table := range schema.Tables {
tableKey := schema.Name + "." + table.Name
if pk, exists := primaryKeys[tableKey]; exists {
table.Constraints[pk.Name] = pk
// Mark columns as primary key and not null
for _, colName := range pk.Columns {
if col, colExists := table.Columns[colName]; colExists {
col.IsPrimaryKey = true
col.NotNull = true
}
}
}
}
// Query foreign keys
foreignKeys, err := r.queryForeignKeys(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query foreign keys for schema %s: %w", schema.Name, err)
}
// Apply foreign keys to tables
for _, table := range schema.Tables {
tableKey := schema.Name + "." + table.Name
if fks, exists := foreignKeys[tableKey]; exists {
for _, fk := range fks {
table.Constraints[fk.Name] = fk
// Derive relationship from foreign key
r.deriveRelationship(table, fk)
}
}
}
// Query unique constraints
uniqueConstraints, err := r.queryUniqueConstraints(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query unique constraints for schema %s: %w", schema.Name, err)
}
// Apply unique constraints to tables
for _, table := range schema.Tables {
tableKey := schema.Name + "." + table.Name
if ucs, exists := uniqueConstraints[tableKey]; exists {
for _, uc := range ucs {
table.Constraints[uc.Name] = uc
}
}
}
// Query check constraints
checkConstraints, err := r.queryCheckConstraints(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query check constraints for schema %s: %w", schema.Name, err)
}
// Apply check constraints to tables
for _, table := range schema.Tables {
tableKey := schema.Name + "." + table.Name
if ccs, exists := checkConstraints[tableKey]; exists {
for _, cc := range ccs {
table.Constraints[cc.Name] = cc
}
}
}
// Query indexes
indexes, err := r.queryIndexes(schema.Name)
if err != nil {
return nil, fmt.Errorf("failed to query indexes for schema %s: %w", schema.Name, err)
}
// Apply indexes to tables
for _, table := range schema.Tables {
tableKey := schema.Name + "." + table.Name
if idxs, exists := indexes[tableKey]; exists {
for _, idx := range idxs {
table.Indexes[idx.Name] = idx
}
}
}
// Set RefDatabase for schema
schema.RefDatabase = db
// Set RefSchema for tables and views
for _, table := range schema.Tables {
table.RefSchema = schema
}
for _, view := range schema.Views {
view.RefSchema = schema
}
for _, seq := range schema.Sequences {
seq.RefSchema = schema
}
// Add schema to database
db.Schemas = append(db.Schemas, schema)
}
return db, nil
}
// ReadSchema reads a single schema (returns the first schema from the database)
func (r *Reader) ReadSchema() (*models.Schema, error) {
db, err := r.ReadDatabase()
if err != nil {
return nil, err
}
if len(db.Schemas) == 0 {
return nil, fmt.Errorf("no schemas found in database")
}
return db.Schemas[0], nil
}
// ReadTable reads a single table (returns the first table from the first schema)
func (r *Reader) ReadTable() (*models.Table, error) {
schema, err := r.ReadSchema()
if err != nil {
return nil, err
}
if len(schema.Tables) == 0 {
return nil, fmt.Errorf("no tables found in schema")
}
return schema.Tables[0], nil
}
// connect establishes a connection to the PostgreSQL database
func (r *Reader) connect() error {
conn, err := pgx.Connect(r.ctx, r.options.ConnectionString)
if err != nil {
return err
}
r.conn = conn
return nil
}
// close closes the database connection
func (r *Reader) close() {
if r.conn != nil {
r.conn.Close(r.ctx)
}
}
// mapDataType maps PostgreSQL data types to canonical types
func (r *Reader) mapDataType(pgType, udtName string) string {
// Map common PostgreSQL types
typeMap := map[string]string{
"integer": "int",
"bigint": "int64",
"smallint": "int16",
"int": "int",
"int2": "int16",
"int4": "int",
"int8": "int64",
"serial": "int",
"bigserial": "int64",
"smallserial": "int16",
"numeric": "decimal",
"decimal": "decimal",
"real": "float32",
"double precision": "float64",
"float4": "float32",
"float8": "float64",
"money": "decimal",
"character varying": "string",
"varchar": "string",
"character": "string",
"char": "string",
"text": "string",
"boolean": "bool",
"bool": "bool",
"date": "date",
"time": "time",
"time without time zone": "time",
"time with time zone": "timetz",
"timestamp": "timestamp",
"timestamp without time zone": "timestamp",
"timestamp with time zone": "timestamptz",
"timestamptz": "timestamptz",
"interval": "interval",
"uuid": "uuid",
"json": "json",
"jsonb": "jsonb",
"bytea": "bytea",
"inet": "inet",
"cidr": "cidr",
"macaddr": "macaddr",
"xml": "xml",
}
// Try mapped type first
if mapped, exists := typeMap[pgType]; exists {
return mapped
}
// Use pgsql utilities if available
if pgsql.ValidSQLType(pgType) {
return pgsql.GetSQLType(pgType)
}
// Return UDT name for custom types
if udtName != "" {
return udtName
}
// Default to the original type
return pgType
}
// deriveRelationship creates a relationship from a foreign key constraint
func (r *Reader) deriveRelationship(table *models.Table, fk *models.Constraint) {
relationshipName := fmt.Sprintf("%s_to_%s", table.Name, fk.ReferencedTable)
relationship := models.InitRelationship(relationshipName, models.OneToMany)
relationship.FromTable = fk.ReferencedTable
relationship.FromSchema = fk.ReferencedSchema
relationship.ToTable = table.Name
relationship.ToSchema = table.Schema
relationship.ForeignKey = fk.Name
// Store constraint actions in properties
if fk.OnDelete != "" {
relationship.Properties["on_delete"] = fk.OnDelete
}
if fk.OnUpdate != "" {
relationship.Properties["on_update"] = fk.OnUpdate
}
table.Relationships[relationshipName] = relationship
}