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

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

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

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

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

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

    35    def to_html(self, **opts) -> LineageHTML:
    36        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, rules: Sequence[Callable] = (<function qualify_tables at 0x7fac3cdc5630>, <function qualify_columns at 0x7fac3cdc4550>, <function expand_laterals at 0x7fac3cd8eb90>), dialect: Union[str, sqlglot.dialects.dialect.Dialect, Type[sqlglot.dialects.dialect.Dialect], NoneType] = None) -> sqlglot.lineage.Node: View Source

     39def lineage(
     40    column: str | exp.Column,
     41    sql: str | exp.Expression,
     42    schema: t.Optional[t.Dict | Schema] = None,
     43    sources: t.Optional[t.Dict[str, str | exp.Subqueryable]] = None,
     44    rules: t.Sequence[t.Callable] = (qualify_tables, qualify_columns, expand_laterals),
     45    dialect: DialectType = None,
     46) -> Node:
     47    """Build the lineage graph for a column of a SQL query.
     48
     49    Args:
     50        column: The column to build the lineage for.
     51        sql: The SQL string or expression.
     52        schema: The schema of tables.
     53        sources: A mapping of queries which will be used to continue building lineage.
     54        rules: Optimizer rules to apply, by default only qualifying tables and columns.
     55        dialect: The dialect of input SQL.
     56
     57    Returns:
     58        A lineage node.
     59    """
     60
     61    expression = maybe_parse(sql, dialect=dialect)
     62
     63    if sources:
     64        expression = exp.expand(
     65            expression,
     66            {
     67                k: t.cast(exp.Subqueryable, maybe_parse(v, dialect=dialect))
     68                for k, v in sources.items()
     69            },
     70        )
     71
     72    optimized = optimize(expression, schema=schema, rules=rules)
     73    scope = build_scope(optimized)
     74
     75    def to_node(
     76        column_name: str,
     77        scope: Scope,
     78        scope_name: t.Optional[str] = None,
     79        upstream: t.Optional[Node] = None,
     80        alias: t.Optional[str] = None,
     81    ) -> Node:
     82        aliases = {
     83            dt.alias: dt.comments[0].split()[1]
     84            for dt in scope.derived_tables
     85            if dt.comments and dt.comments[0].startswith("source: ")
     86        }
     87        if isinstance(scope.expression, exp.Union):
     88            for scope in scope.union_scopes:
     89                node = to_node(
     90                    column_name,
     91                    scope=scope,
     92                    scope_name=scope_name,
     93                    upstream=upstream,
     94                    alias=aliases.get(scope_name),
     95                )
     96            return node
     97
     98        # Find the specific select clause that is the source of the column we want.
     99        # This can either be a specific, named select or a generic `*` clause.
    100        select = next(
    101            (select for select in scope.selects if select.alias_or_name == column_name),
    102            exp.Star() if scope.expression.is_star else None,
    103        )
    104
    105        if not select:
    106            raise ValueError(f"Could not find {column_name} in {scope.expression}")
    107
    108        if isinstance(scope.expression, exp.Select):
    109            # For better ergonomics in our node labels, replace the full select with
    110            # a version that has only the column we care about.
    111            #   "x", SELECT x, y FROM foo
    112            #     => "x", SELECT x FROM foo
    113            source = optimize(
    114                scope.expression.select(select, append=False), schema=schema, rules=rules
    115            )
    116            select = source.selects[0]
    117        else:
    118            source = scope.expression
    119
    120        # Create the node for this step in the lineage chain, and attach it to the previous one.
    121        node = Node(
    122            name=f"{scope_name}.{column_name}" if scope_name else column_name,
    123            source=source,
    124            expression=select,
    125            alias=alias or "",
    126        )
    127        if upstream:
    128            upstream.downstream.append(node)
    129
    130        # Find all columns that went into creating this one to list their lineage nodes.
    131        for c in set(select.find_all(exp.Column)):
    132            table = c.table
    133            source = scope.sources.get(table)
    134
    135            if isinstance(source, Scope):
    136                # The table itself came from a more specific scope. Recurse into that one using the unaliased column name.
    137                to_node(
    138                    c.name, scope=source, scope_name=table, upstream=node, alias=aliases.get(table)
    139                )
    140            else:
    141                # The source is not a scope - we've reached the end of the line. At this point, if a source is not found
    142                # it means this column's lineage is unknown. This can happen if the definition of a source used in a query
    143                # is not passed into the `sources` map.
    144                source = source or exp.Placeholder()
    145                node.downstream.append(Node(name=c.sql(), source=source, expression=source))
    146
    147        return node
    148
    149    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.
- rules: Optimizer rules to apply, by default only qualifying tables and columns.
- dialect: The dialect of input SQL.

###### Returns:

> A lineage node.

class LineageHTML: View Source

    152class LineageHTML:
    153    """Node to HTML generator using vis.js.
    154
    155    https://visjs.github.io/vis-network/docs/network/
    156    """
    157
    158    def __init__(
    159        self,
    160        node: Node,
    161        dialect: DialectType = None,
    162        imports: bool = True,
    163        **opts: t.Any,
    164    ):
    165        self.node = node
    166        self.imports = imports
    167
    168        self.options = {
    169            "height": "500px",
    170            "width": "100%",
    171            "layout": {
    172                "hierarchical": {
    173                    "enabled": True,
    174                    "nodeSpacing": 200,
    175                    "sortMethod": "directed",
    176                },
    177            },
    178            "interaction": {
    179                "dragNodes": False,
    180                "selectable": False,
    181            },
    182            "physics": {
    183                "enabled": False,
    184            },
    185            "edges": {
    186                "arrows": "to",
    187            },
    188            "nodes": {
    189                "font": "20px monaco",
    190                "shape": "box",
    191                "widthConstraint": {
    192                    "maximum": 300,
    193                },
    194            },
    195            **opts,
    196        }
    197
    198        self.nodes = {}
    199        self.edges = []
    200
    201        for node in node.walk():
    202            if isinstance(node.expression, exp.Table):
    203                label = f"FROM {node.expression.this}"
    204                title = f"<pre>SELECT {node.name} FROM {node.expression.this}</pre>"
    205                group = 1
    206            else:
    207                label = node.expression.sql(pretty=True, dialect=dialect)
    208                source = node.source.transform(
    209                    lambda n: exp.Tag(this=n, prefix="<b>", postfix="</b>")
    210                    if n is node.expression
    211                    else n,
    212                    copy=False,
    213                ).sql(pretty=True, dialect=dialect)
    214                title = f"<pre>{source}</pre>"
    215                group = 0
    216
    217            node_id = id(node)
    218
    219            self.nodes[node_id] = {
    220                "id": node_id,
    221                "label": label,
    222                "title": title,
    223                "group": group,
    224            }
    225
    226            for d in node.downstream:
    227                self.edges.append({"from": node_id, "to": id(d)})
    228
    229    def __str__(self):
    230        nodes = json.dumps(list(self.nodes.values()))
    231        edges = json.dumps(self.edges)
    232        options = json.dumps(self.options)
    233        imports = (
    234            """<script type="text/javascript" src="https://unpkg.com/vis-data@latest/peer/umd/vis-data.min.js"></script>
    235  <script type="text/javascript" src="https://unpkg.com/vis-network@latest/peer/umd/vis-network.min.js"></script>
    236  <link rel="stylesheet" type="text/css" href="https://unpkg.com/vis-network/styles/vis-network.min.css" />"""
    237            if self.imports
    238            else ""
    239        )
    240
    241        return f"""<div>
    242  <div id="sqlglot-lineage"></div>
    243  {imports}
    244  <script type="text/javascript">
    245    var nodes = new vis.DataSet({nodes})
    246    nodes.forEach(row => row["title"] = new DOMParser().parseFromString(row["title"], "text/html").body.childNodes[0])
    247
    248    new vis.Network(
    249        document.getElementById("sqlglot-lineage"),
    250        {{
    251            nodes: nodes,
    252            edges: new vis.DataSet({edges})
    253        }},
    254        {options},
    255    )
    256  </script>
    257</div>"""
    258
    259    def _repr_html_(self) -> str:
    260        return self.__str__()

Node to HTML generator using vis.js.

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

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

    158    def __init__(
    159        self,
    160        node: Node,
    161        dialect: DialectType = None,
    162        imports: bool = True,
    163        **opts: t.Any,
    164    ):
    165        self.node = node
    166        self.imports = imports
    167
    168        self.options = {
    169            "height": "500px",
    170            "width": "100%",
    171            "layout": {
    172                "hierarchical": {
    173                    "enabled": True,
    174                    "nodeSpacing": 200,
    175                    "sortMethod": "directed",
    176                },
    177            },
    178            "interaction": {
    179                "dragNodes": False,
    180                "selectable": False,
    181            },
    182            "physics": {
    183                "enabled": False,
    184            },
    185            "edges": {
    186                "arrows": "to",
    187            },
    188            "nodes": {
    189                "font": "20px monaco",
    190                "shape": "box",
    191                "widthConstraint": {
    192                    "maximum": 300,
    193                },
    194            },
    195            **opts,
    196        }
    197
    198        self.nodes = {}
    199        self.edges = []
    200
    201        for node in node.walk():
    202            if isinstance(node.expression, exp.Table):
    203                label = f"FROM {node.expression.this}"
    204                title = f"<pre>SELECT {node.name} FROM {node.expression.this}</pre>"
    205                group = 1
    206            else:
    207                label = node.expression.sql(pretty=True, dialect=dialect)
    208                source = node.source.transform(
    209                    lambda n: exp.Tag(this=n, prefix="<b>", postfix="</b>")
    210                    if n is node.expression
    211                    else n,
    212                    copy=False,
    213                ).sql(pretty=True, dialect=dialect)
    214                title = f"<pre>{source}</pre>"
    215                group = 0
    216
    217            node_id = id(node)
    218
    219            self.nodes[node_id] = {
    220                "id": node_id,
    221                "label": label,
    222                "title": title,
    223                "group": group,
    224            }
    225
    226            for d in node.downstream:
    227                self.edges.append({"from": node_id, "to": id(d)})