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Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Collected ¶
Collected groups extracted rows by table name. Ordering for emission is the caller's responsibility (see internal/plan.Build).
func Walk ¶
func Walk( ctx context.Context, db *sql.DB, d dialect.Dialect, schema introspect.Schema, seedTable, whereClause string, dir Direction, ) (*Collected, error)
Walk extracts rows from a seed (seedTable + whereClause) and recursively collects the FK-connected closure in the given direction: parents for Forward (clone), referencing children for Backward (delete).
An empty whereClause selects every row in seedTable (no WHERE filter is appended). The CLI rejects empty filters; this is for callers that want to operate on the full contents of a small lookup table.
Composite primary keys, composite foreign keys, and self-referencing FKs are all supported. Within a single table, callers order the row slice with SortByPK: emit it as-is for Forward (referenced rows first), reversed for Backward (referencing rows first).
type Direction ¶
type Direction int
Direction selects which way Walk traverses the FK graph from the seed.
const ( // Forward collects the FK parents a row references (clone). Emit the // result parents-first so every INSERT lands after its referenced rows. Forward Direction = iota // Backward collects the rows that reference a row (delete). Emit the // result most-dependent-first so every DELETE runs before the row it // depends on. Backward )
type Row ¶
Row maps column names to scanned values for one extracted row.
func SortByPK ¶
func SortByPK(rows []Row, table introspect.Table) ([]Row, error)
SortByPK reorders rows so that any self-referencing FK is satisfied at apply time: a row whose FK column points to another row in the same slice will appear after its parent. Tables without a self-ref FK are returned unchanged.
v0.1 supports single-column self-ref FKs against single-column PKs. Composite self-ref FKs or composite PKs return an error. Cyclic data (e.g., A -> B -> A) also returns an error: the apply step would need a DEFERRABLE constraint to succeed, which is out of scope.
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