sqlglot.lineage API documentation

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# sqlglot.lineage

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      1from __future__ import annotations
      2
      3import json
      4import typing as t
      5from dataclasses import dataclass, field
      6
      7from sqlglot import Schema, exp, maybe_parse
      8from sqlglot.errors import SqlglotError
      9from sqlglot.optimizer import Scope, build_scope, qualify
     10
     11if t.TYPE_CHECKING:
     12    from sqlglot.dialects.dialect import DialectType
     13
     14
     15@dataclass(frozen=True)
     16class Node:
     17    name: str
     18    expression: exp.Expression
     19    source: exp.Expression
     20    downstream: t.List[Node] = field(default_factory=list)
     21    alias: str = ""
     22
     23    def walk(self) -> t.Iterator[Node]:
     24        yield self
     25
     26        for d in self.downstream:
     27            if isinstance(d, Node):
     28                yield from d.walk()
     29            else:
     30                yield d
     31
     32    def to_html(self, **opts) -> LineageHTML:
     33        return LineageHTML(self, **opts)
     34
     35
     36def lineage(
     37    column: str | exp.Column,
     38    sql: str | exp.Expression,
     39    schema: t.Optional[t.Dict | Schema] = None,
     40    sources: t.Optional[t.Dict[str, str | exp.Subqueryable]] = None,
     41    dialect: DialectType = None,
     42    **kwargs,
     43) -> Node:
     44    """Build the lineage graph for a column of a SQL query.
     45
     46    Args:
     47        column: The column to build the lineage for.
     48        sql: The SQL string or expression.
     49        schema: The schema of tables.
     50        sources: A mapping of queries which will be used to continue building lineage.
     51        dialect: The dialect of input SQL.
     52        **kwargs: Qualification optimizer kwargs.
     53
     54    Returns:
     55        A lineage node.
     56    """
     57
     58    expression = maybe_parse(sql, dialect=dialect)
     59
     60    if sources:
     61        expression = exp.expand(
     62            expression,
     63            {
     64                k: t.cast(exp.Subqueryable, maybe_parse(v, dialect=dialect))
     65                for k, v in sources.items()
     66            },
     67        )
     68
     69    qualified = qualify.qualify(
     70        expression,
     71        dialect=dialect,
     72        schema=schema,
     73        **{"validate_qualify_columns": False, "identify": False, **kwargs},  # type: ignore
     74    )
     75
     76    scope = build_scope(qualified)
     77
     78    if not scope:
     79        raise SqlglotError("Cannot build lineage, sql must be SELECT")
     80
     81    def to_node(
     82        column: str | int,
     83        scope: Scope,
     84        scope_name: t.Optional[str] = None,
     85        upstream: t.Optional[Node] = None,
     86        alias: t.Optional[str] = None,
     87    ) -> Node:
     88        aliases = {
     89            dt.alias: dt.comments[0].split()[1]
     90            for dt in scope.derived_tables
     91            if dt.comments and dt.comments[0].startswith("source: ")
     92        }
     93
     94        # Find the specific select clause that is the source of the column we want.
     95        # This can either be a specific, named select or a generic `*` clause.
     96        select = (
     97            scope.expression.selects[column]
     98            if isinstance(column, int)
     99            else next(
    100                (select for select in scope.expression.selects if select.alias_or_name == column),
    101                exp.Star() if scope.expression.is_star else None,
    102            )
    103        )
    104
    105        if not select:
    106            raise ValueError(f"Could not find {column} in {scope.expression}")
    107
    108        if isinstance(scope.expression, exp.Union):
    109            upstream = upstream or Node(name="UNION", source=scope.expression, expression=select)
    110
    111            index = (
    112                column
    113                if isinstance(column, int)
    114                else next(
    115                    i
    116                    for i, select in enumerate(scope.expression.selects)
    117                    if select.alias_or_name == column
    118                )
    119            )
    120
    121            for s in scope.union_scopes:
    122                to_node(index, scope=s, upstream=upstream)
    123
    124            return upstream
    125
    126        subquery = select.unalias()
    127
    128        if isinstance(subquery, exp.Subquery):
    129            upstream = upstream or Node(name="SUBQUERY", source=scope.expression, expression=select)
    130            scope = t.cast(Scope, build_scope(subquery.unnest()))
    131
    132            for select in subquery.named_selects:
    133                to_node(select, scope=scope, upstream=upstream)
    134
    135            return upstream
    136
    137        if isinstance(scope.expression, exp.Select):
    138            # For better ergonomics in our node labels, replace the full select with
    139            # a version that has only the column we care about.
    140            #   "x", SELECT x, y FROM foo
    141            #     => "x", SELECT x FROM foo
    142            source = t.cast(exp.Expression, scope.expression.select(select, append=False))
    143        else:
    144            source = scope.expression
    145
    146        # Create the node for this step in the lineage chain, and attach it to the previous one.
    147        node = Node(
    148            name=f"{scope_name}.{column}" if scope_name else str(column),
    149            source=source,
    150            expression=select,
    151            alias=alias or "",
    152        )
    153        if upstream:
    154            upstream.downstream.append(node)
    155
    156        # Find all columns that went into creating this one to list their lineage nodes.
    157        source_columns = set(select.find_all(exp.Column))
    158
    159        # If the source is a UDTF find columns used in the UTDF to generate the table
    160        if isinstance(source, exp.UDTF):
    161            source_columns |= set(source.find_all(exp.Column))
    162
    163        for c in source_columns:
    164            table = c.table
    165            source = scope.sources.get(table)
    166
    167            if isinstance(source, Scope):
    168                # The table itself came from a more specific scope. Recurse into that one using the unaliased column name.
    169                to_node(
    170                    c.name, scope=source, scope_name=table, upstream=node, alias=aliases.get(table)
    171                )
    172            else:
    173                # The source is not a scope - we've reached the end of the line. At this point, if a source is not found
    174                # it means this column's lineage is unknown. This can happen if the definition of a source used in a query
    175                # is not passed into the `sources` map.
    176                source = source or exp.Placeholder()
    177                node.downstream.append(Node(name=c.sql(), source=source, expression=source))
    178
    179        return node
    180
    181    return to_node(column if isinstance(column, str) else column.name, scope)
    182
    183
    184class LineageHTML:
    185    """Node to HTML generator using vis.js.
    186
    187    https://visjs.github.io/vis-network/docs/network/
    188    """
    189
    190    def __init__(
    191        self,
    192        node: Node,
    193        dialect: DialectType = None,
    194        imports: bool = True,
    195        **opts: t.Any,
    196    ):
    197        self.node = node
    198        self.imports = imports
    199
    200        self.options = {
    201            "height": "500px",
    202            "width": "100%",
    203            "layout": {
    204                "hierarchical": {
    205                    "enabled": True,
    206                    "nodeSpacing": 200,
    207                    "sortMethod": "directed",
    208                },
    209            },
    210            "interaction": {
    211                "dragNodes": False,
    212                "selectable": False,
    213            },
    214            "physics": {
    215                "enabled": False,
    216            },
    217            "edges": {
    218                "arrows": "to",
    219            },
    220            "nodes": {
    221                "font": "20px monaco",
    222                "shape": "box",
    223                "widthConstraint": {
    224                    "maximum": 300,
    225                },
    226            },
    227            **opts,
    228        }
    229
    230        self.nodes = {}
    231        self.edges = []
    232
    233        for node in node.walk():
    234            if isinstance(node.expression, exp.Table):
    235                label = f"FROM {node.expression.this}"
    236                title = f"<pre>SELECT {node.name} FROM {node.expression.this}</pre>"
    237                group = 1
    238            else:
    239                label = node.expression.sql(pretty=True, dialect=dialect)
    240                source = node.source.transform(
    241                    lambda n: exp.Tag(this=n, prefix="<b>", postfix="</b>")
    242                    if n is node.expression
    243                    else n,
    244                    copy=False,
    245                ).sql(pretty=True, dialect=dialect)
    246                title = f"<pre>{source}</pre>"
    247                group = 0
    248
    249            node_id = id(node)
    250
    251            self.nodes[node_id] = {
    252                "id": node_id,
    253                "label": label,
    254                "title": title,
    255                "group": group,
    256            }
    257
    258            for d in node.downstream:
    259                self.edges.append({"from": node_id, "to": id(d)})
    260
    261    def __str__(self):
    262        nodes = json.dumps(list(self.nodes.values()))
    263        edges = json.dumps(self.edges)
    264        options = json.dumps(self.options)
    265        imports = (
    266            """<script type="text/javascript" src="https://unpkg.com/vis-data@latest/peer/umd/vis-data.min.js"></script>
    267  <script type="text/javascript" src="https://unpkg.com/vis-network@latest/peer/umd/vis-network.min.js"></script>
    268  <link rel="stylesheet" type="text/css" href="https://unpkg.com/vis-network/styles/vis-network.min.css" />"""
    269            if self.imports
    270            else ""
    271        )
    272
    273        return f"""<div>
    274  <div id="sqlglot-lineage"></div>
    275  {imports}
    276  <script type="text/javascript">
    277    var nodes = new vis.DataSet({nodes})
    278    nodes.forEach(row => row["title"] = new DOMParser().parseFromString(row["title"], "text/html").body.childNodes[0])
    279
    280    new vis.Network(
    281        document.getElementById("sqlglot-lineage"),
    282        {{
    283            nodes: nodes,
    284            edges: new vis.DataSet({edges})
    285        }},
    286        {options},
    287    )
    288  </script>
    289</div>"""
    290
    291    def _repr_html_(self) -> str:
    292        return self.__str__()

@dataclass(frozen=True)
class Node: View Source

    16@dataclass(frozen=True)
    17class Node:
    18    name: str
    19    expression: exp.Expression
    20    source: exp.Expression
    21    downstream: t.List[Node] = field(default_factory=list)
    22    alias: str = ""
    23
    24    def walk(self) -> t.Iterator[Node]:
    25        yield self
    26
    27        for d in self.downstream:
    28            if isinstance(d, Node):
    29                yield from d.walk()
    30            else:
    31                yield d
    32
    33    def to_html(self, **opts) -> LineageHTML:
    34        return LineageHTML(self, **opts)

Node( name: str, expression: sqlglot.expressions.Expression, source: sqlglot.expressions.Expression, downstream: List[Node] = <factory>, alias: str = '')
name: str
expression: sqlglot.expressions.Expression
source: sqlglot.expressions.Expression
downstream: List[Node]
alias: str = ''
def walk(self) -> Iterator[Node]: View Source

    24    def walk(self) -> t.Iterator[Node]:
    25        yield self
    26
    27        for d in self.downstream:
    28            if isinstance(d, Node):
    29                yield from d.walk()
    30            else:
    31                yield d

def to_html(self, **opts) -> LineageHTML: View Source

    33    def to_html(self, **opts) -> LineageHTML:
    34        return LineageHTML(self, **opts)

def lineage( column: str | sqlglot.expressions.Column, sql: str | sqlglot.expressions.Expression, schema: Union[Dict, sqlglot.schema.Schema, NoneType] = None, sources: Optional[Dict[str, str | sqlglot.expressions.Subqueryable]] = None, dialect: Union[str, sqlglot.dialects.dialect.Dialect, Type[sqlglot.dialects.dialect.Dialect], NoneType] = None, **kwargs) -> Node: View Source

     37def lineage(
     38    column: str | exp.Column,
     39    sql: str | exp.Expression,
     40    schema: t.Optional[t.Dict | Schema] = None,
     41    sources: t.Optional[t.Dict[str, str | exp.Subqueryable]] = None,
     42    dialect: DialectType = None,
     43    **kwargs,
     44) -> Node:
     45    """Build the lineage graph for a column of a SQL query.
     46
     47    Args:
     48        column: The column to build the lineage for.
     49        sql: The SQL string or expression.
     50        schema: The schema of tables.
     51        sources: A mapping of queries which will be used to continue building lineage.
     52        dialect: The dialect of input SQL.
     53        **kwargs: Qualification optimizer kwargs.
     54
     55    Returns:
     56        A lineage node.
     57    """
     58
     59    expression = maybe_parse(sql, dialect=dialect)
     60
     61    if sources:
     62        expression = exp.expand(
     63            expression,
     64            {
     65                k: t.cast(exp.Subqueryable, maybe_parse(v, dialect=dialect))
     66                for k, v in sources.items()
     67            },
     68        )
     69
     70    qualified = qualify.qualify(
     71        expression,
     72        dialect=dialect,
     73        schema=schema,
     74        **{"validate_qualify_columns": False, "identify": False, **kwargs},  # type: ignore
     75    )
     76
     77    scope = build_scope(qualified)
     78
     79    if not scope:
     80        raise SqlglotError("Cannot build lineage, sql must be SELECT")
     81
     82    def to_node(
     83        column: str | int,
     84        scope: Scope,
     85        scope_name: t.Optional[str] = None,
     86        upstream: t.Optional[Node] = None,
     87        alias: t.Optional[str] = None,
     88    ) -> Node:
     89        aliases = {
     90            dt.alias: dt.comments[0].split()[1]
     91            for dt in scope.derived_tables
     92            if dt.comments and dt.comments[0].startswith("source: ")
     93        }
     94
     95        # Find the specific select clause that is the source of the column we want.
     96        # This can either be a specific, named select or a generic `*` clause.
     97        select = (
     98            scope.expression.selects[column]
     99            if isinstance(column, int)
    100            else next(
    101                (select for select in scope.expression.selects if select.alias_or_name == column),
    102                exp.Star() if scope.expression.is_star else None,
    103            )
    104        )
    105
    106        if not select:
    107            raise ValueError(f"Could not find {column} in {scope.expression}")
    108
    109        if isinstance(scope.expression, exp.Union):
    110            upstream = upstream or Node(name="UNION", source=scope.expression, expression=select)
    111
    112            index = (
    113                column
    114                if isinstance(column, int)
    115                else next(
    116                    i
    117                    for i, select in enumerate(scope.expression.selects)
    118                    if select.alias_or_name == column
    119                )
    120            )
    121
    122            for s in scope.union_scopes:
    123                to_node(index, scope=s, upstream=upstream)
    124
    125            return upstream
    126
    127        subquery = select.unalias()
    128
    129        if isinstance(subquery, exp.Subquery):
    130            upstream = upstream or Node(name="SUBQUERY", source=scope.expression, expression=select)
    131            scope = t.cast(Scope, build_scope(subquery.unnest()))
    132
    133            for select in subquery.named_selects:
    134                to_node(select, scope=scope, upstream=upstream)
    135
    136            return upstream
    137
    138        if isinstance(scope.expression, exp.Select):
    139            # For better ergonomics in our node labels, replace the full select with
    140            # a version that has only the column we care about.
    141            #   "x", SELECT x, y FROM foo
    142            #     => "x", SELECT x FROM foo
    143            source = t.cast(exp.Expression, scope.expression.select(select, append=False))
    144        else:
    145            source = scope.expression
    146
    147        # Create the node for this step in the lineage chain, and attach it to the previous one.
    148        node = Node(
    149            name=f"{scope_name}.{column}" if scope_name else str(column),
    150            source=source,
    151            expression=select,
    152            alias=alias or "",
    153        )
    154        if upstream:
    155            upstream.downstream.append(node)
    156
    157        # Find all columns that went into creating this one to list their lineage nodes.
    158        source_columns = set(select.find_all(exp.Column))
    159
    160        # If the source is a UDTF find columns used in the UTDF to generate the table
    161        if isinstance(source, exp.UDTF):
    162            source_columns |= set(source.find_all(exp.Column))
    163
    164        for c in source_columns:
    165            table = c.table
    166            source = scope.sources.get(table)
    167
    168            if isinstance(source, Scope):
    169                # The table itself came from a more specific scope. Recurse into that one using the unaliased column name.
    170                to_node(
    171                    c.name, scope=source, scope_name=table, upstream=node, alias=aliases.get(table)
    172                )
    173            else:
    174                # The source is not a scope - we've reached the end of the line. At this point, if a source is not found
    175                # it means this column's lineage is unknown. This can happen if the definition of a source used in a query
    176                # is not passed into the `sources` map.
    177                source = source or exp.Placeholder()
    178                node.downstream.append(Node(name=c.sql(), source=source, expression=source))
    179
    180        return node
    181
    182    return to_node(column if isinstance(column, str) else column.name, scope)

Build the lineage graph for a column of a SQL query.

###### Arguments:

- column: The column to build the lineage for.
- sql: The SQL string or expression.
- schema: The schema of tables.
- sources: A mapping of queries which will be used to continue building lineage.
- dialect: The dialect of input SQL.
- **kwargs: Qualification optimizer kwargs.

###### Returns:

> A lineage node.

class LineageHTML: View Source

    185class LineageHTML:
    186    """Node to HTML generator using vis.js.
    187
    188    https://visjs.github.io/vis-network/docs/network/
    189    """
    190
    191    def __init__(
    192        self,
    193        node: Node,
    194        dialect: DialectType = None,
    195        imports: bool = True,
    196        **opts: t.Any,
    197    ):
    198        self.node = node
    199        self.imports = imports
    200
    201        self.options = {
    202            "height": "500px",
    203            "width": "100%",
    204            "layout": {
    205                "hierarchical": {
    206                    "enabled": True,
    207                    "nodeSpacing": 200,
    208                    "sortMethod": "directed",
    209                },
    210            },
    211            "interaction": {
    212                "dragNodes": False,
    213                "selectable": False,
    214            },
    215            "physics": {
    216                "enabled": False,
    217            },
    218            "edges": {
    219                "arrows": "to",
    220            },
    221            "nodes": {
    222                "font": "20px monaco",
    223                "shape": "box",
    224                "widthConstraint": {
    225                    "maximum": 300,
    226                },
    227            },
    228            **opts,
    229        }
    230
    231        self.nodes = {}
    232        self.edges = []
    233
    234        for node in node.walk():
    235            if isinstance(node.expression, exp.Table):
    236                label = f"FROM {node.expression.this}"
    237                title = f"<pre>SELECT {node.name} FROM {node.expression.this}</pre>"
    238                group = 1
    239            else:
    240                label = node.expression.sql(pretty=True, dialect=dialect)
    241                source = node.source.transform(
    242                    lambda n: exp.Tag(this=n, prefix="<b>", postfix="</b>")
    243                    if n is node.expression
    244                    else n,
    245                    copy=False,
    246                ).sql(pretty=True, dialect=dialect)
    247                title = f"<pre>{source}</pre>"
    248                group = 0
    249
    250            node_id = id(node)
    251
    252            self.nodes[node_id] = {
    253                "id": node_id,
    254                "label": label,
    255                "title": title,
    256                "group": group,
    257            }
    258
    259            for d in node.downstream:
    260                self.edges.append({"from": node_id, "to": id(d)})
    261
    262    def __str__(self):
    263        nodes = json.dumps(list(self.nodes.values()))
    264        edges = json.dumps(self.edges)
    265        options = json.dumps(self.options)
    266        imports = (
    267            """<script type="text/javascript" src="https://unpkg.com/vis-data@latest/peer/umd/vis-data.min.js"></script>
    268  <script type="text/javascript" src="https://unpkg.com/vis-network@latest/peer/umd/vis-network.min.js"></script>
    269  <link rel="stylesheet" type="text/css" href="https://unpkg.com/vis-network/styles/vis-network.min.css" />"""
    270            if self.imports
    271            else ""
    272        )
    273
    274        return f"""<div>
    275  <div id="sqlglot-lineage"></div>
    276  {imports}
    277  <script type="text/javascript">
    278    var nodes = new vis.DataSet({nodes})
    279    nodes.forEach(row => row["title"] = new DOMParser().parseFromString(row["title"], "text/html").body.childNodes[0])
    280
    281    new vis.Network(
    282        document.getElementById("sqlglot-lineage"),
    283        {{
    284            nodes: nodes,
    285            edges: new vis.DataSet({edges})
    286        }},
    287        {options},
    288    )
    289  </script>
    290</div>"""
    291
    292    def _repr_html_(self) -> str:
    293        return self.__str__()

Node to HTML generator using vis.js.

https://visjs.github.io/vis-network/docs/network/

LineageHTML( node: Node, dialect: Union[str, sqlglot.dialects.dialect.Dialect, Type[sqlglot.dialects.dialect.Dialect], NoneType] = None, imports: bool = True, **opts: Any) View Source

    191    def __init__(
    192        self,
    193        node: Node,
    194        dialect: DialectType = None,
    195        imports: bool = True,
    196        **opts: t.Any,
    197    ):
    198        self.node = node
    199        self.imports = imports
    200
    201        self.options = {
    202            "height": "500px",
    203            "width": "100%",
    204            "layout": {
    205                "hierarchical": {
    206                    "enabled": True,
    207                    "nodeSpacing": 200,
    208                    "sortMethod": "directed",
    209                },
    210            },
    211            "interaction": {
    212                "dragNodes": False,
    213                "selectable": False,
    214            },
    215            "physics": {
    216                "enabled": False,
    217            },
    218            "edges": {
    219                "arrows": "to",
    220            },
    221            "nodes": {
    222                "font": "20px monaco",
    223                "shape": "box",
    224                "widthConstraint": {
    225                    "maximum": 300,
    226                },
    227            },
    228            **opts,
    229        }
    230
    231        self.nodes = {}
    232        self.edges = []
    233
    234        for node in node.walk():
    235            if isinstance(node.expression, exp.Table):
    236                label = f"FROM {node.expression.this}"
    237                title = f"<pre>SELECT {node.name} FROM {node.expression.this}</pre>"
    238                group = 1
    239            else:
    240                label = node.expression.sql(pretty=True, dialect=dialect)
    241                source = node.source.transform(
    242                    lambda n: exp.Tag(this=n, prefix="<b>", postfix="</b>")
    243                    if n is node.expression
    244                    else n,
    245                    copy=False,
    246                ).sql(pretty=True, dialect=dialect)
    247                title = f"<pre>{source}</pre>"
    248                group = 0
    249
    250            node_id = id(node)
    251
    252            self.nodes[node_id] = {
    253                "id": node_id,
    254                "label": label,
    255                "title": title,
    256                "group": group,
    257            }
    258
    259            for d in node.downstream:
    260                self.edges.append({"from": node_id, "to": id(d)})

node
imports
options
nodes
edges